diff --git a/libvips/include/vips/arithmetic.h b/libvips/include/vips/arithmetic.h
index d3afca98..d775e373 100644
--- a/libvips/include/vips/arithmetic.h
+++ b/libvips/include/vips/arithmetic.h
@@ -31,8 +31,8 @@
 
  */
 
-#ifndef IM_ARITHMETIC_H
-#define IM_ARITHMETIC_H
+#ifndef VIPS_ARITHMETIC_H
+#define VIPS_ARITHMETIC_H
 
 #ifdef __cplusplus
 extern "C" {
@@ -46,16 +46,16 @@ extern "C" {
  * @VIPS_OPERATION_MATH_ASIN: asin(), angles in degrees
  * @VIPS_OPERATION_MATH_ACOS: acos(), angles in degrees
  * @VIPS_OPERATION_MATH_ATAN: atan(), angles in degrees
+ * @VIPS_OPERATION_MATH_LOG: log base e 
+ * @VIPS_OPERATION_MATH_LOG10: log base 10 
+ * @VIPS_OPERATION_MATH_EXP: e to the something
+ * @VIPS_OPERATION_MATH_EXP10: 10 to the something
  * @VIPS_OPERATION_MATH_SINH: sinh(), angles in radians
  * @VIPS_OPERATION_MATH_COSH: cosh(), angles in radians
  * @VIPS_OPERATION_MATH_TANH: tanh(), angles in radians
  * @VIPS_OPERATION_MATH_ASINH: asinh(), angles in radians
  * @VIPS_OPERATION_MATH_ACOSH: acosh(), angles in radians
  * @VIPS_OPERATION_MATH_ATANH: atanh(), angles in radians
- * @VIPS_OPERATION_MATH_LOG: log base e 
- * @VIPS_OPERATION_MATH_LOG10: log base 10 
- * @VIPS_OPERATION_MATH_EXP: e to the something
- * @VIPS_OPERATION_MATH_EXP10: 10 to the something
  *
  * See also: vips_math().
  */
@@ -66,16 +66,16 @@ typedef enum {
 	VIPS_OPERATION_MATH_ASIN,
 	VIPS_OPERATION_MATH_ACOS,
 	VIPS_OPERATION_MATH_ATAN,
+	VIPS_OPERATION_MATH_LOG,
+	VIPS_OPERATION_MATH_LOG10,
+	VIPS_OPERATION_MATH_EXP,
+	VIPS_OPERATION_MATH_EXP10,
 	VIPS_OPERATION_MATH_SINH,
 	VIPS_OPERATION_MATH_COSH,
 	VIPS_OPERATION_MATH_TANH,
 	VIPS_OPERATION_MATH_ASINH,
 	VIPS_OPERATION_MATH_ACOSH,
 	VIPS_OPERATION_MATH_ATANH,
-	VIPS_OPERATION_MATH_LOG,
-	VIPS_OPERATION_MATH_LOG10,
-	VIPS_OPERATION_MATH_EXP,
-	VIPS_OPERATION_MATH_EXP10,
 	VIPS_OPERATION_MATH_LAST
 } VipsOperationMath;
 
@@ -443,4 +443,4 @@ int vips_profile( VipsImage *in, VipsImage **columns, VipsImage **rows, ... )
 }
 #endif /*__cplusplus*/
 
-#endif /*IM_ARITHMETIC_H*/
+#endif /*VIPS_ARITHMETIC_H*/
diff --git a/libvips/iofuncs/enumtypes.c b/libvips/iofuncs/enumtypes.c
index 8d78dbd7..a963c5c3 100644
--- a/libvips/iofuncs/enumtypes.c
+++ b/libvips/iofuncs/enumtypes.c
@@ -18,16 +18,16 @@ vips_operation_math_get_type( void )
 			{VIPS_OPERATION_MATH_ASIN, "VIPS_OPERATION_MATH_ASIN", "asin"},
 			{VIPS_OPERATION_MATH_ACOS, "VIPS_OPERATION_MATH_ACOS", "acos"},
 			{VIPS_OPERATION_MATH_ATAN, "VIPS_OPERATION_MATH_ATAN", "atan"},
+			{VIPS_OPERATION_MATH_LOG, "VIPS_OPERATION_MATH_LOG", "log"},
+			{VIPS_OPERATION_MATH_LOG10, "VIPS_OPERATION_MATH_LOG10", "log10"},
+			{VIPS_OPERATION_MATH_EXP, "VIPS_OPERATION_MATH_EXP", "exp"},
+			{VIPS_OPERATION_MATH_EXP10, "VIPS_OPERATION_MATH_EXP10", "exp10"},
 			{VIPS_OPERATION_MATH_SINH, "VIPS_OPERATION_MATH_SINH", "sinh"},
 			{VIPS_OPERATION_MATH_COSH, "VIPS_OPERATION_MATH_COSH", "cosh"},
 			{VIPS_OPERATION_MATH_TANH, "VIPS_OPERATION_MATH_TANH", "tanh"},
 			{VIPS_OPERATION_MATH_ASINH, "VIPS_OPERATION_MATH_ASINH", "asinh"},
 			{VIPS_OPERATION_MATH_ACOSH, "VIPS_OPERATION_MATH_ACOSH", "acosh"},
 			{VIPS_OPERATION_MATH_ATANH, "VIPS_OPERATION_MATH_ATANH", "atanh"},
-			{VIPS_OPERATION_MATH_LOG, "VIPS_OPERATION_MATH_LOG", "log"},
-			{VIPS_OPERATION_MATH_LOG10, "VIPS_OPERATION_MATH_LOG10", "log10"},
-			{VIPS_OPERATION_MATH_EXP, "VIPS_OPERATION_MATH_EXP", "exp"},
-			{VIPS_OPERATION_MATH_EXP10, "VIPS_OPERATION_MATH_EXP10", "exp10"},
 			{VIPS_OPERATION_MATH_LAST, "VIPS_OPERATION_MATH_LAST", "last"},
 			{0, NULL, NULL}
 		};