diff --git a/examples/ffi-jni-call-06-jdouble-return.sx b/examples/ffi-jni-call-06-jdouble-return.sx
new file mode 100644
index 0000000..6a12105
--- /dev/null
+++ b/examples/ffi-jni-call-06-jdouble-return.sx
@@ -0,0 +1,19 @@
+// Phase 1 step 1.20 (PLAN-FFI.md): `#jni_call(f64)` (jdouble return).
+// First non-integer return type for JNI — exercises the LLVM
+// `double` ret path through CallDoubleMethod (vtable slot 58).
+
+#import "modules/std.sx";
+
+g_should_call : bool = false;
+
+read_double :: (env: *void, target: *void) -> f64 {
+    #jni_call(f64)(env, target, "getValue", "()D");
+}
+
+main :: () -> s32 {
+    if g_should_call {
+        _ := read_double(null, null);
+    }
+    print("ok\n");
+    0;
+}
diff --git a/tests/expected/ffi-jni-call-06-jdouble-return.exit b/tests/expected/ffi-jni-call-06-jdouble-return.exit
new file mode 100644
index 0000000..573541a
--- /dev/null
+++ b/tests/expected/ffi-jni-call-06-jdouble-return.exit
@@ -0,0 +1 @@
+0
diff --git a/tests/expected/ffi-jni-call-06-jdouble-return.ir b/tests/expected/ffi-jni-call-06-jdouble-return.ir
new file mode 100644
index 0000000..6c4587d
--- /dev/null
+++ b/tests/expected/ffi-jni-call-06-jdouble-return.ir
@@ -0,0 +1,269 @@
+
+@context = internal global { { ptr, ptr, ptr }, ptr } zeroinitializer
+@g_should_call = internal global i1 false
+@str = private unnamed_addr constant [9 x i8] c"getValue\00", align 1
+@str.1 = private unnamed_addr constant [4 x i8] c"()D\00", align 1
+@str.2 = private unnamed_addr constant [4 x i8] c"ok\0A\00", align 1
+@str.3 = private unnamed_addr constant [1 x i8] zeroinitializer, align 1
+
+; Function Attrs: nounwind
+declare void @out(ptr) #0
+
+declare ptr @malloc(i64)
+
+declare ptr @memcpy(ptr, ptr, i64)
+
+declare ptr @memset(ptr, i32, i64)
+
+declare void @free(ptr)
+
+; Function Attrs: nounwind
+declare void @GPA.create(ptr sret({ ptr, ptr, ptr }), ptr) #0
+
+; Function Attrs: nounwind
+define internal ptr @GPA.alloc(ptr %0, i64 %1) #0 {
+entry:
+  %alloca = alloca ptr, align 8
+  store ptr %0, ptr %alloca, align 8
+  %allocaN = alloca i64, align 8
+  store i64 %1, ptr %allocaN, align 8
+  %load = load ptr, ptr %alloca, align 8
+  %gep = getelementptr inbounds { i64 }, ptr %load, i32 0, i32 0
+  %loadN = load i64, ptr %gep, align 8
+  %add = add i64 %loadN, 1
+  store i64 %add, ptr %gep, align 8
+  %loadN = load i64, ptr %allocaN, align 8
+  %malloc = call ptr @malloc(i64 %loadN)
+  ret ptr %malloc
+}
+
+; Function Attrs: nounwind
+define internal void @GPA.dealloc(ptr %0, ptr %1) #0 {
+entry:
+  %alloca = alloca ptr, align 8
+  store ptr %0, ptr %alloca, align 8
+  %allocaN = alloca ptr, align 8
+  store ptr %1, ptr %allocaN, align 8
+  %load = load ptr, ptr %alloca, align 8
+  %gep = getelementptr inbounds { i64 }, ptr %load, i32 0, i32 0
+  %loadN = load i64, ptr %gep, align 8
+  %sub = sub i64 %loadN, 1
+  store i64 %sub, ptr %gep, align 8
+  %loadN = load ptr, ptr %allocaN, align 8
+  call void @free(ptr %loadN)
+  ret void
+}
+
+; Function Attrs: nounwind
+declare void @Arena.add_chunk(ptr, i64) #0
+
+; Function Attrs: nounwind
+declare void @Arena.create(ptr sret({ ptr, ptr, ptr }), ptr, ptr, i64) #0
+
+; Function Attrs: nounwind
+declare void @Arena.reset(ptr) #0
+
+; Function Attrs: nounwind
+declare void @Arena.deinit(ptr) #0
+
+; Function Attrs: nounwind
+declare ptr @Arena.alloc(ptr, i64) #0
+
+; Function Attrs: nounwind
+declare void @Arena.dealloc(ptr, ptr) #0
+
+; Function Attrs: nounwind
+declare void @BufAlloc.create(ptr sret({ ptr, ptr, ptr }), ptr, ptr, i64) #0
+
+; Function Attrs: nounwind
+declare void @BufAlloc.reset(ptr) #0
+
+; Function Attrs: nounwind
+declare ptr @BufAlloc.alloc(ptr, i64) #0
+
+; Function Attrs: nounwind
+declare void @BufAlloc.dealloc(ptr, ptr) #0
+
+; Function Attrs: nounwind
+define internal { ptr, i64 } @cstring(i64 %0) #0 {
+entry:
+  %alloca = alloca i64, align 8
+  store i64 %0, ptr %alloca, align 8
+  %load = load i64, ptr %alloca, align 8
+  %add = add i64 %load, 1
+  %heap = call ptr @malloc(i64 %add)
+  %allocaN = alloca ptr, align 8
+  store ptr %heap, ptr %allocaN, align 8
+  %loadN = load ptr, ptr %allocaN, align 8
+  %loadN = load i64, ptr %alloca, align 8
+  %addN = add i64 %loadN, 1
+  %1 = call ptr @memset(ptr %loadN, i32 0, i64 %addN)
+  %allocaN = alloca { ptr, i64 }, align 8
+  store { ptr, i64 } undef, ptr %allocaN, align 8
+  %loadN = load ptr, ptr %allocaN, align 8
+  %gep = getelementptr inbounds { ptr, i64 }, ptr %allocaN, i32 0, i32 0
+  %pti = ptrtoint ptr %loadN to i64
+  store i64 %pti, ptr %gep, align 8
+  %loadN = load i64, ptr %alloca, align 8
+  %gepN = getelementptr inbounds { ptr, i64 }, ptr %allocaN, i32 0, i32 1
+  store i64 %loadN, ptr %gepN, align 8
+  %loadN = load { ptr, i64 }, ptr %allocaN, align 8
+  ret { ptr, i64 } %loadN
+}
+
+; Function Attrs: nounwind
+declare ptr @int_to_string(i64) #0
+
+; Function Attrs: nounwind
+declare ptr @bool_to_string(i1) #0
+
+; Function Attrs: nounwind
+declare ptr @float_to_string(double) #0
+
+; Function Attrs: nounwind
+declare void @hex_group(ptr, i64, i64) #0
+
+; Function Attrs: nounwind
+declare ptr @int_to_hex_string(i64) #0
+
+; Function Attrs: nounwind
+define internal { ptr, i64 } @concat({ ptr, i64 } %0, { ptr, i64 } %1) #0 {
+entry:
+  %alloca = alloca { ptr, i64 }, align 8
+  store { ptr, i64 } %0, ptr %alloca, align 8
+  %allocaN = alloca { ptr, i64 }, align 8
+  store { ptr, i64 } %1, ptr %allocaN, align 8
+  %load = load { ptr, i64 }, ptr %alloca, align 8
+  %len = extractvalue { ptr, i64 } %load, 1
+  %allocaN = alloca i64, align 8
+  store i64 %len, ptr %allocaN, align 8
+  %loadN = load { ptr, i64 }, ptr %allocaN, align 8
+  %lenN = extractvalue { ptr, i64 } %loadN, 1
+  %allocaN = alloca i64, align 8
+  store i64 %lenN, ptr %allocaN, align 8
+  %loadN = load i64, ptr %allocaN, align 8
+  %loadN = load i64, ptr %allocaN, align 8
+  %add = add i64 %loadN, %loadN
+  %call = call { ptr, i64 } @cstring(i64 %add)
+  %allocaN = alloca { ptr, i64 }, align 8
+  store { ptr, i64 } %call, ptr %allocaN, align 8
+  %loadN = load { ptr, i64 }, ptr %allocaN, align 8
+  %dptr = extractvalue { ptr, i64 } %loadN, 0
+  %loadN = load { ptr, i64 }, ptr %alloca, align 8
+  %dptrN = extractvalue { ptr, i64 } %loadN, 0
+  %loadN = load i64, ptr %allocaN, align 8
+  %2 = call ptr @memcpy(ptr %dptr, ptr %dptrN, i64 %loadN)
+  %loadN = load i64, ptr %allocaN, align 8
+  %loadN = load { ptr, i64 }, ptr %allocaN, align 8
+  %igp.data = extractvalue { ptr, i64 } %loadN, 0
+  %igp.ptr = getelementptr i8, ptr %igp.data, i64 %loadN
+  %loadN = load { ptr, i64 }, ptr %allocaN, align 8
+  %dptrN = extractvalue { ptr, i64 } %loadN, 0
+  %loadN = load i64, ptr %allocaN, align 8
+  %3 = call ptr @memcpy(ptr %igp.ptr, ptr %dptrN, i64 %loadN)
+  %loadN = load { ptr, i64 }, ptr %allocaN, align 8
+  ret { ptr, i64 } %loadN
+}
+
+; Function Attrs: nounwind
+define internal { ptr, i64 } @substr({ ptr, i64 } %0, i64 %1, i64 %2) #0 {
+entry:
+  %alloca = alloca { ptr, i64 }, align 8
+  store { ptr, i64 } %0, ptr %alloca, align 8
+  %allocaN = alloca i64, align 8
+  store i64 %1, ptr %allocaN, align 8
+  %allocaN = alloca i64, align 8
+  store i64 %2, ptr %allocaN, align 8
+  %load = load i64, ptr %allocaN, align 8
+  %call = call { ptr, i64 } @cstring(i64 %load)
+  %allocaN = alloca { ptr, i64 }, align 8
+  store { ptr, i64 } %call, ptr %allocaN, align 8
+  %loadN = load { ptr, i64 }, ptr %allocaN, align 8
+  %dptr = extractvalue { ptr, i64 } %loadN, 0
+  %loadN = load i64, ptr %allocaN, align 8
+  %loadN = load { ptr, i64 }, ptr %alloca, align 8
+  %igp.data = extractvalue { ptr, i64 } %loadN, 0
+  %igp.ptr = getelementptr i8, ptr %igp.data, i64 %loadN
+  %loadN = load i64, ptr %allocaN, align 8
+  %3 = call ptr @memcpy(ptr %dptr, ptr %igp.ptr, i64 %loadN)
+  %loadN = load { ptr, i64 }, ptr %allocaN, align 8
+  ret { ptr, i64 } %loadN
+}
+
+; Function Attrs: nounwind
+declare ptr @any_to_string([2 x i64]) #0
+
+; Function Attrs: nounwind
+declare ptr @build_format(ptr) #0
+
+; Function Attrs: nounwind
+define internal double @read_double(ptr %0, ptr %1) #0 {
+entry:
+  %alloca = alloca ptr, align 8
+  store ptr %0, ptr %alloca, align 8
+  %allocaN = alloca ptr, align 8
+  store ptr %1, ptr %allocaN, align 8
+  %load = load ptr, ptr %alloca, align 8
+  %loadN = load ptr, ptr %allocaN, align 8
+  ret double undef
+}
+
+; Function Attrs: nounwind
+define i32 @main() #0 {
+entry:
+  %alloca = alloca { i64 }, align 8
+  store { i64 } zeroinitializer, ptr %alloca, align 8
+  %si = insertvalue { ptr, ptr, ptr } undef, ptr %alloca, 0
+  %siN = insertvalue { ptr, ptr, ptr } %si, ptr @__thunk_GPA_Allocator_alloc, 1
+  %siN = insertvalue { ptr, ptr, ptr } %siN, ptr @__thunk_GPA_Allocator_dealloc, 2
+  %siN = insertvalue { { ptr, ptr, ptr }, ptr } undef, { ptr, ptr, ptr } %siN, 0
+  %siN = insertvalue { { ptr, ptr, ptr }, ptr } %siN, ptr null, 1
+  store { { ptr, ptr, ptr }, ptr } %siN, ptr @context, align 8
+  %gload = load i1, ptr @g_should_call, align 1
+  br i1 %gload, label %if.then.0, label %if.merge.1
+
+if.then.0:                                        ; preds = %entry
+  %call = call double @read_double(ptr null, ptr null)
+  %allocaN = alloca double, align 8
+  store double %call, ptr %allocaN, align 8
+  br label %if.merge.1
+
+if.merge.1:                                       ; preds = %if.then.0, %entry
+  %allocaN = alloca { ptr, i64 }, align 8
+  %gep = getelementptr inbounds { ptr, i64 }, ptr %allocaN, i32 0, i32 0
+  store ptr null, ptr %gep, align 8
+  %gepN = getelementptr inbounds { ptr, i64 }, ptr %allocaN, i32 0, i32 1
+  store i64 0, ptr %gepN, align 8
+  %allocaN = alloca { ptr, i64 }, align 8
+  store { ptr, i64 } { ptr @str.2, i64 3 }, ptr %allocaN, align 8
+  %allocaN = alloca { ptr, i64 }, align 8
+  store { ptr, i64 } { ptr @str.3, i64 0 }, ptr %allocaN, align 8
+  %load = load { ptr, i64 }, ptr %allocaN, align 8
+  %loadN = load { ptr, i64 }, ptr %allocaN, align 8
+  %callN = call { ptr, i64 } @substr({ ptr, i64 } %loadN, i64 0, i64 3)
+  %callN = call { ptr, i64 } @concat({ ptr, i64 } %load, { ptr, i64 } %callN)
+  store { ptr, i64 } %callN, ptr %allocaN, align 8
+  %loadN = load { ptr, i64 }, ptr %allocaN, align 8
+  %str.ptr = extractvalue { ptr, i64 } %loadN, 0
+  %str.len = extractvalue { ptr, i64 } %loadN, 1
+  %0 = call i64 @write(i32 1, ptr %str.ptr, i64 %str.len)
+  ret i32 0
+}
+
+; Function Attrs: nounwind
+define internal ptr @__thunk_GPA_Allocator_alloc(ptr %0, i64 %1) #0 {
+entry:
+  %call = call ptr @GPA.alloc(ptr %0, i64 %1)
+  ret ptr %call
+}
+
+; Function Attrs: nounwind
+define internal void @__thunk_GPA_Allocator_dealloc(ptr %0, ptr %1) #0 {
+entry:
+  call void @GPA.dealloc(ptr %0, ptr %1)
+  ret void
+}
+
+declare i64 @write(i32, ptr, i64)
+
+
diff --git a/tests/expected/ffi-jni-call-06-jdouble-return.txt b/tests/expected/ffi-jni-call-06-jdouble-return.txt
new file mode 100644
index 0000000..9766475
--- /dev/null
+++ b/tests/expected/ffi-jni-call-06-jdouble-return.txt
@@ -0,0 +1 @@
+ok