diff --git a/sysdeps/m68k/fpu/bits/mathdef.h b/sysdeps/m68k/fpu/bits/mathdef.h
index 7b09882e12..c3365a7ff2 100644
--- a/sysdeps/m68k/fpu/bits/mathdef.h
+++ b/sysdeps/m68k/fpu/bits/mathdef.h
@@ -38,7 +38,7 @@ typedef long double double_t;	/* `double' expressions are evaluated as
 # define INFINITY	HUGE_VALF
 
 /* The values returned by `ilogb' for 0 and NaN respectively.  */
-# define FP_ILOGB0	(-2147483648)
+# define FP_ILOGB0	(-2147483647 - 1)
 # define FP_ILOGBNAN	(2147483647)
 
 /* Number of decimal digits for the `long double' type.  */