diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp
index 8b58df49c27..b1e9f941fe8 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp
@@ -1858,6 +1858,8 @@ CodeEmitterGM107::emitIMAD()
 void
 CodeEmitterGM107::emitISCADD()
 {
+   assert(insn->src(1).get()->asImm());
+
    switch (insn->src(2).getFile()) {
    case FILE_GPR:
       emitInsn(0x5c180000);