diff --git a/MagickCore/display.c b/MagickCore/display.c
index cca29f2..59906bf 100644
--- a/MagickCore/display.c
+++ b/MagickCore/display.c
@@ -3541,7 +3541,7 @@
               break;
             if (entry != 5)
               {
-                (*image)->fuzz=SiPrefixToDouble(FuzzMenu[entry],1.0*
+                (*image)->fuzz=SiPrefixToDouble(FuzzMenu[entry],(double)
                   QuantumRange+1.0);
                 break;
               }
@@ -3551,7 +3551,7 @@
             if (*fuzz == '\0')
               break;
             (void) ConcatenateMagickString(fuzz,"%",MaxTextExtent);
-            (*image)->fuzz=SiPrefixToDouble(fuzz,1.0*QuantumRange+1.0);
+            (*image)->fuzz=SiPrefixToDouble(fuzz,(double) QuantumRange+1.0);
             break;
           }
           case ColorEditUndoCommand:
@@ -9854,7 +9854,7 @@
               break;
             if (entry != 5)
               {
-                (*image)->fuzz=SiPrefixToDouble(FuzzMenu[entry],1.0*
+                (*image)->fuzz=SiPrefixToDouble(FuzzMenu[entry],(double)
                   QuantumRange+1.0);
                 break;
               }
@@ -9864,7 +9864,7 @@
             if (*fuzz == '\0')
               break;
             (void) ConcatenateMagickString(fuzz,"%",MaxTextExtent);
-            (*image)->fuzz=SiPrefixToDouble(fuzz,1.0*QuantumRange+1.0);
+            (*image)->fuzz=SiPrefixToDouble(fuzz,(double) QuantumRange+1.0);
             break;
           }
           case MatteEditValueCommand:
diff --git a/MagickCore/image.c b/MagickCore/image.c
index bf79a47..3633366 100644
--- a/MagickCore/image.c
+++ b/MagickCore/image.c
@@ -4248,7 +4248,7 @@
       MagickFalse,option);
   option=GetImageOption(image_info,"fuzz");
   if (option != (const char *) NULL)
-    image->fuzz=SiPrefixToDouble(option,QuantumRange);
+    image->fuzz=SiPrefixToDouble(option,(double) QuantumRange+1.0);
   option=GetImageOption(image_info,"gravity");
   if (option != (const char *) NULL)
     image->gravity=(GravityType) ParseCommandOption(MagickGravityOptions,
diff --git a/MagickCore/string-private.h b/MagickCore/string-private.h
index b3dd2e1..6e4308c 100644
--- a/MagickCore/string-private.h
+++ b/MagickCore/string-private.h
@@ -31,6 +31,9 @@
     scale,
     value;
 
+  /*
+    Interpret string with International System of Units (SI) unit prefix.
+  */
   value=InterpretLocaleValue(string,&q);
   scale=1000.0;
   if ((*q != '\0') && (tolower((int) ((unsigned char) *(q+1))) == 'i'))