diff --git a/compiler/src/prog8/compiler/target/c64/codegen/assignment/AugmentableAssignmentAsmGen.kt b/compiler/src/prog8/compiler/target/c64/codegen/assignment/AugmentableAssignmentAsmGen.kt
index 43a984718..c724644ca 100644
--- a/compiler/src/prog8/compiler/target/c64/codegen/assignment/AugmentableAssignmentAsmGen.kt
+++ b/compiler/src/prog8/compiler/target/c64/codegen/assignment/AugmentableAssignmentAsmGen.kt
@@ -217,8 +217,9 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
             if(!childIDt.isKnown)
                 throw AssemblyError("unknown dt")
             val childDt = childIDt.typeOrElse(DataType.STRUCT)
-            if (value.type.equalsSize(childDt) || value.type.largerThan(childDt)) {
+            if (value.type!=DataType.FLOAT && (value.type.equalsSize(childDt) || value.type.largerThan(childDt))) {
                 // this typecast is redundant here; the rest of the code knows how to deal with the uncasted value.
+                // (works for integer types, not for float.)
                 inplaceModification(target, operator, value.expression)
                 return true
             }
diff --git a/examples/test.p8 b/examples/test.p8
index 3ef92e80d..7ddc104b4 100644
--- a/examples/test.p8
+++ b/examples/test.p8
@@ -6,16 +6,37 @@
 main {
 
     sub start() {
-        float t = 0.0
 
-        repeat 10 {
-            float cosa = cos(t)
-            float sina = sin(t)
-            float cosb = cos(t*0.33)
-            float sinb = sin(t*0.33)
-            float cosc = cos(t*0.78)
-            float sinc = sin(t*0.78)
-        }
+;        byte bb = 4
+;        bb += sgn(bb+bb)
+;        txt.print_b(bb)
+;        txt.chrout('\n')
+;
+;        word ww = 4
+;        ww += sgn(ww+ww)
+;        txt.print_w(ww)
+;        txt.chrout('\n')
+
+        float x = 4
+        x += abs(x+x)
+        floats.print_f(x)
+        txt.chrout('\n')
+
+        x = 4
+        x += sgn(x+x)           ; TODO missing byte->float cast in assembly???  Also fucks up stack
+        x += sgn(x+x)           ; TODO missing byte->float cast in assembly???  Also fucks up stack
+        x += sgn(x+x)           ; TODO missing byte->float cast in assembly???  Also fucks up stack
+        floats.print_f(x)
+        txt.chrout('\n')
+
+;        repeat 10 {
+;            float cosa = cos(t)
+;            float sina = sin(t)
+;            float cosb = cos(t*0.33)
+;            float sinb = sin(t*0.33)
+;            float cosc = cos(t*0.78)
+;            float sinc = sin(t*0.78)
+;        }
 
         testX()
     }