diff --git a/gcc/config/m68k/m68k.cc b/gcc/config/m68k/m68k.cc
index e9325686b92..6cd45b53406 100644
--- a/gcc/config/m68k/m68k.cc
+++ b/gcc/config/m68k/m68k.cc
@@ -5471,7 +5471,7 @@ output_andsi3 (rtx *operands)
 	operands[1] = GEN_INT (logval);
       else
         {
-	  operands[0] = adjust_address (operands[0], SImode, 3 - (logval / 8));
+	  operands[0] = adjust_address (operands[0], QImode, 3 - (logval / 8));
 	  operands[1] = GEN_INT (logval % 8);
         }
       return "bclr %1,%0";
@@ -5510,7 +5510,7 @@ output_iorsi3 (rtx *operands)
 	operands[1] = GEN_INT (logval);
       else
         {
-	  operands[0] = adjust_address (operands[0], SImode, 3 - (logval / 8));
+	  operands[0] = adjust_address (operands[0], QImode, 3 - (logval / 8));
 	  operands[1] = GEN_INT (logval % 8);
 	}
       return "bset %1,%0";
@@ -5548,7 +5548,7 @@ output_xorsi3 (rtx *operands)
 	operands[1] = GEN_INT (logval);
       else
         {
-	  operands[0] = adjust_address (operands[0], SImode, 3 - (logval / 8));
+	  operands[0] = adjust_address (operands[0], QImode, 3 - (logval / 8));
 	  operands[1] = GEN_INT (logval % 8);
 	}
       return "bchg %1,%0";
diff --git a/gcc/testsuite/gcc.target/m68k/pr108640.c b/gcc/testsuite/gcc.target/m68k/pr108640.c
new file mode 100644
index 00000000000..5f3e8b49d42
--- /dev/null
+++ b/gcc/testsuite/gcc.target/m68k/pr108640.c
@@ -0,0 +1,7 @@
+/* { dg-do compile } */
+/* { do-options "-O1" } */
+
+int x;
+void andsi3(void) { x &= ~(1 << 16); }
+void iorsi3(void) { x |=  (1 << 16); }
+void xorsi3(void) { x ^=  (1 << 16); }