diff --git a/src/cmd/5g/gsubr.c b/src/cmd/5g/gsubr.c
index ef5a509147..dbcfc233be 100644
--- a/src/cmd/5g/gsubr.c
+++ b/src/cmd/5g/gsubr.c
@@ -1812,6 +1812,8 @@ sudoaddable(int as, Node *n, Addr *a, int *w)
 	if(n->type == T)
 		return 0;
 
+	memset(a, 0, sizeof *a);
+
 	switch(n->op) {
 	case OLITERAL:
 		if(!isconst(n, CTINT))
diff --git a/src/cmd/6g/gsubr.c b/src/cmd/6g/gsubr.c
index 697016c6f3..51409e467b 100644
--- a/src/cmd/6g/gsubr.c
+++ b/src/cmd/6g/gsubr.c
@@ -1966,6 +1966,8 @@ sudoaddable(int as, Node *n, Addr *a)
 	if(n->type == T)
 		return 0;
 
+	memset(a, 0, sizeof *a);
+
 	switch(n->op) {
 	case OLITERAL:
 		if(!isconst(n, CTINT))
diff --git a/src/cmd/8g/gsubr.c b/src/cmd/8g/gsubr.c
index dd75e9f092..af1963f980 100644
--- a/src/cmd/8g/gsubr.c
+++ b/src/cmd/8g/gsubr.c
@@ -2398,7 +2398,7 @@ sudoaddable(int as, Node *n, Addr *a)
 {
 	USED(as);
 	USED(n);
-	USED(a);
 
+	memset(a, 0, sizeof *a);
 	return 0;
 }
diff --git a/src/cmd/9g/gsubr.c b/src/cmd/9g/gsubr.c
index 49f184d51e..073324ee12 100644
--- a/src/cmd/9g/gsubr.c
+++ b/src/cmd/9g/gsubr.c
@@ -1700,6 +1700,7 @@ int
 sudoaddable(int as, Node *n, Addr *a)
 {
 	// TODO(minux)
-	USED(as); USED(n); USED(a);
+	USED(as); USED(n);
+	memset(a, 0, sizeof *a);
 	return 0;
 }