diff --git a/internal/fs/fs.go b/internal/fs/fs.go
index 0741591bda..e1e56979dd 100644
--- a/internal/fs/fs.go
+++ b/internal/fs/fs.go
@@ -401,7 +401,7 @@ func (fs *fileSystem) checkInvariants() {
 	for _, v := range fs.generationBackedInodes {
 		if fs.inodes[v.ID()] != v {
 			panic(fmt.Sprintf(
-				"Mismatch for ID %v: %p %p",
+				"Mismatch for ID %v: %v %v",
 				v.ID(),
 				fs.inodes[v.ID()],
 				v))
@@ -426,7 +426,7 @@ func (fs *fileSystem) checkInvariants() {
 	for _, v := range fs.implicitDirInodes {
 		if fs.inodes[v.ID()] != v {
 			panic(fmt.Sprintf(
-				"Mismatch for ID %v: %p %p",
+				"Mismatch for ID %v: %v %v",
 				v.ID(),
 				fs.inodes[v.ID()],
 				v))
@@ -452,7 +452,7 @@ func (fs *fileSystem) checkInvariants() {
 		if dir && !edir {
 			if !(fs.implicitDirInodes[in.Name()] == in) {
 				panic(fmt.Sprintf(
-					"implicitDirInodes mismatch: %q %p %p",
+					"implicitDirInodes mismatch: %q %v %v",
 					in.Name(),
 					fs.implicitDirInodes[in.Name()],
 					in))
diff --git a/internal/gcsx/random_reader.go b/internal/gcsx/random_reader.go
index d9b8d008e3..981af5efc1 100644
--- a/internal/gcsx/random_reader.go
+++ b/internal/gcsx/random_reader.go
@@ -86,7 +86,7 @@ type randomReader struct {
 func (rr *randomReader) CheckInvariants() {
 	// INVARIANT: (reader == nil) == (cancel == nil)
 	if (rr.reader == nil) != (rr.cancel == nil) {
-		panic(fmt.Sprintf("Mismatch: %v vs. %v", rr.reader, rr.cancel))
+		panic(fmt.Sprintf("Mismatch: %v vs. %v", rr.reader == nil, rr.cancel == nil))
 	}
 
 	// INVARIANT: start <= limit