diff --git a/ChangeLog b/ChangeLog
index c1a05d31..0fc484d3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -6,6 +6,7 @@
 - fix memleak in tiff pyr save to memory [scossu]
 - istiff attempts to read the first directory rather than just testing the
 magic number [przemyslawpluta]
+- much faster ismagick() [jcupitt]
 
 21/9/18 started 8.8.0
 - much faster smartcrop [lovell]
diff --git a/libvips/foreign/magick.c b/libvips/foreign/magick.c
index 5119b7ed..367a4ba5 100644
--- a/libvips/foreign/magick.c
+++ b/libvips/foreign/magick.c
@@ -641,4 +641,16 @@ magick_set_magick_profile( Image *image,
 	return( 0 );
 }
 
+/* Does a few bytes look like a file IM can handle?
+ */
+gboolean
+magick_ismagick( const unsigned char *buf, size_t length )
+{
+	char format[MagickPathExtent];
+
+	magick_genesis();
+
+	return( GetImageMagick( buf, length, format ) );
+}
+
 #endif /*HAVE_MAGICK*/
diff --git a/libvips/foreign/magick.h b/libvips/foreign/magick.h
index 8993a31e..9c9be67d 100644
--- a/libvips/foreign/magick.h
+++ b/libvips/foreign/magick.h
@@ -84,4 +84,6 @@ int magick_set_vips_profile( VipsImage *im, Image *image );
 int magick_set_magick_profile( Image *image, 
 	VipsImage *im, ExceptionInfo *exception );
 
+gboolean magick_ismagick( const unsigned char *buf, size_t length );
+
 #endif /*HAVE_MAGICK6*/
diff --git a/libvips/foreign/magick7load.c b/libvips/foreign/magick7load.c
index 6592ff74..5c0ceb76 100644
--- a/libvips/foreign/magick7load.c
+++ b/libvips/foreign/magick7load.c
@@ -757,26 +757,15 @@ G_DEFINE_TYPE( VipsForeignLoadMagick7File, vips_foreign_load_magick7_file,
 static gboolean
 ismagick7( const char *filename )
 {
-	Image *image;
-	ImageInfo *image_info;
-	ExceptionInfo *exception;
-	int result;
-
-	magick_genesis();
-
-	/* Horribly slow :-(
+	/* Fetch the first 100 bytes. Hopefully that'll be enough.
 	 */
-	image_info = CloneImageInfo( NULL );
-	exception = magick_acquire_exception();
-	vips_strncpy( image_info->filename, filename, MagickPathExtent );
-	magick_sniff_file( image_info, filename );
-	image = PingImage( image_info, exception );
-	result = image != NULL;
-	VIPS_FREEF( DestroyImageList, image );
-	VIPS_FREEF( DestroyImageInfo, image_info ); 
-	VIPS_FREEF( magick_destroy_exception, exception ); 
+	unsigned char buf[100];
 
-	return( result );
+	/* Files shorter than 100 bytes will leave nonsense at the end of buf,
+	 * but it shouldn't matter.
+	 */
+	return( vips__get_bytes( filename, buf, 100 ) &&
+		magick_ismagick( buf, 100 ) );
 }
 
 static int
@@ -860,25 +849,7 @@ G_DEFINE_TYPE( VipsForeignLoadMagick7Buffer, vips_foreign_load_magick7_buffer,
 static gboolean
 vips_foreign_load_magick7_buffer_is_a_buffer( const void *buf, size_t len )
 {
-	Image *image;
-	ImageInfo *image_info;
-	ExceptionInfo *exception;
-	int result;
-
-	magick_genesis();
-
-	/* Horribly slow :-(
-	 */
-	image_info = CloneImageInfo( NULL );
-	exception = magick_acquire_exception();
-	magick_sniff_bytes( image_info, buf, len );
-	image = PingBlob( image_info, buf, len, exception );
-	result = image != NULL;
-	VIPS_FREEF( DestroyImageList, image );
-	VIPS_FREEF( DestroyImageInfo, image_info ); 
-	VIPS_FREEF( magick_destroy_exception, exception ); 
-
-	return( result );
+	return( magick_ismagick( (const unsigned char *) buf, len ) );
 }
 
 static int
diff --git a/libvips/foreign/magickload.c b/libvips/foreign/magickload.c
index 9643805e..a1215a30 100644
--- a/libvips/foreign/magickload.c
+++ b/libvips/foreign/magickload.c
@@ -63,6 +63,7 @@
 #ifdef HAVE_MAGICK6
 
 #include "pforeign.h"
+#include "magick.h"
 
 typedef struct _VipsForeignLoadMagick {
 	VipsForeignLoad parent_object;
@@ -172,16 +173,15 @@ G_DEFINE_TYPE( VipsForeignLoadMagickFile, vips_foreign_load_magick_file,
 static gboolean
 ismagick( const char *filename )
 {
-	VipsImage *t;
-	int result;
+	/* Fetch the first 100 bytes. Hopefully that'll be enough.
+	 */
+	unsigned char buf[100];
 
-	t = vips_image_new();
-	vips_error_freeze();
-	result = vips__magick_read_header( filename, t, NULL, 0, 1 );
-	g_object_unref( t );
-	vips_error_thaw();
-
-	return( result == 0 );
+	/* Files shorter than 100 bytes will leave nonsense at the end of buf,
+	 * but it shouldn't matter.
+	 */
+	return( vips__get_bytes( filename, buf, 100 ) &&
+		magick_ismagick( buf, 100 ) );
 }
 
 /* Unfortunately, libMagick does not support header-only reads very well. See
@@ -258,16 +258,7 @@ G_DEFINE_TYPE( VipsForeignLoadMagickBuffer, vips_foreign_load_magick_buffer,
 static gboolean
 vips_foreign_load_magick_buffer_is_a_buffer( const void *buf, size_t len )
 {
-	VipsImage *t;
-	int result;
-
-	t = vips_image_new();
-	vips_error_freeze();
-	result = vips__magick_read_buffer_header( buf, len, t, NULL, 0, 1 );
-	g_object_unref( t );
-	vips_error_thaw();
-
-	return( result == 0 );
+	return( magick_ismagick( (const unsigned char *) buf, len ) );
 }
 
 /* Unfortunately, libMagick does not support header-only reads very well. See