diff --git a/libvips/include/vips/debug.h b/libvips/include/vips/debug.h
index 71a9732a..13b8443d 100644
--- a/libvips/include/vips/debug.h
+++ b/libvips/include/vips/debug.h
@@ -43,6 +43,23 @@ extern GSList *im__open_images;
 void im__print_one( int n );
 void im__print_all( void );
 
+const char *im_Type2char( VipsType type );
+const char *im_BandFmt2char( VipsBandFmt fmt );
+const char *im_Coding2char( VipsCoding coding );
+const char *im_Compression2char( int n );
+const char *im_dtype2char( im_desc_type n );
+const char *im_dhint2char( VipsDemandStyle style );
+
+int im_char2Type( const char *str );
+int im_char2BandFmt( const char *str );
+int im_char2Coding( const char *str );
+int im_char2Compression( const char *str );
+im_desc_type im_char2dtype( const char *str );
+im_demand_type im_char2dhint( const char *str );
+
+void im_printdesc( IMAGE *image );
+int im_image_sanity( IMAGE *im );
+
 #ifdef __cplusplus
 }
 #endif /*__cplusplus*/
diff --git a/libvips/include/vips/proto.h b/libvips/include/vips/proto.h
index 101bb4b4..84ea1898 100644
--- a/libvips/include/vips/proto.h
+++ b/libvips/include/vips/proto.h
@@ -147,16 +147,6 @@ int im_existsf( const char *name, ... )
 int im_isvips( const char * );
 
 int im_bits_of_fmt( VipsBandFmt fmt );
-const char *im_Type2char( VipsType type );
-const char *im_BandFmt2char( VipsBandFmt fmt );
-const char *im_Coding2char( VipsCoding coding );
-const char *im_Compression2char( int );
-const char *im_dhint2char( VipsDemandStyle style );
-const char *im_dtype2char( im_desc_type );
-int im_char2Type( const char * );
-int im_char2BandFmt( const char * );
-int im_char2Coding( const char * );
-int im_char2Compression( const char * );
 
 int im_unmapfile( IMAGE * );
 void im_printdesc( IMAGE * );