--- a/layout/style/nsCSSScanner.cpp
+++ b/layout/style/nsCSSScanner.cpp
@@ -876,17 +876,17 @@ nsCSSScanner::ScanNumber(nsCSSToken& aTo
       fracPart += DecimalDigitValue(c) / divisor;
       divisor *= 10;
       Advance();
       c = Peek();
     } while (IsDigit(c));
   }
 
   bool gotE = false;
-  if (IsSVGMode() && (c == 'e' || c == 'E')) {
+  if (c == 'e' || c == 'E') {
     int32_t expSignChar = Peek(1);
     int32_t nextChar = Peek(2);
     if (IsDigit(expSignChar) ||
         ((expSignChar == '-' || expSignChar == '+') && IsDigit(nextChar))) {
       gotE = true;
       if (expSignChar == '-') {
         expSign = -1;
       }

--- a/layout/style/test/property_database.js
+++ b/layout/style/test/property_database.js
@@ -2850,18 +2850,18 @@ var gCSSProperties = {
 		],
 		invalid_values: [ "auto", "none", "5" ]
 	},
 
 	"opacity": {
 		domProp: "opacity",
 		inherited: false,
 		type: CSS_TYPE_LONGHAND,
-		initial_values: [ "1", "17", "397.376" ],
-		other_values: [ "0", "0.4", "0.0000", "-3" ],
+		initial_values: [ "1", "17", "397.376", "3e1", "3e+1", "3e0", "3e+0", "3e-0" ],
+		other_values: [ "0", "0.4", "0.0000", "-3", "3e-1" ],
 		invalid_values: [ "0px", "1px" ]
 	},
 	"-moz-orient": {
 		domProp: "MozOrient",
 		inherited: false,
 		type: CSS_TYPE_LONGHAND,
 		initial_values: [ "auto" ],
 		other_values: [ "horizontal", "vertical" ],
@@ -2870,17 +2870,17 @@ var gCSSProperties = {
 	"orphans": {
 		domProp: "orphans",
 		inherited: true,
 		backend_only: true,
 		type: CSS_TYPE_LONGHAND,
 		// XXX requires display:block
 		initial_values: [ "2" ],
 		other_values: [ "1", "7" ],
-		invalid_values: [ "0", "-1", "0px", "3px" ]
+		invalid_values: [ "0", "-1", "0px", "3px", "3e1" ]
 	},
 	"outline": {
 		domProp: "outline",
 		inherited: false,
 		type: CSS_TYPE_TRUE_SHORTHAND,
 		subproperties: [ "outline-color", "outline-style", "outline-width" ],
 		initial_values: [
 			"none", "medium", "thin",
@@ -3342,27 +3342,31 @@ var gCSSProperties = {
 	"widows": {
 		domProp: "widows",
 		inherited: true,
 		backend_only: true,
 		type: CSS_TYPE_LONGHAND,
 		// XXX requires display:block
 		initial_values: [ "2" ],
 		other_values: [ "1", "7" ],
-		invalid_values: [ "0", "-1", "0px", "3px" ]
+		invalid_values: [ "0", "-1", "0px", "3px", "3e1" ]
 	},
 	"width": {
 		domProp: "width",
 		inherited: false,
 		type: CSS_TYPE_LONGHAND,
 		/* computed value tests for width test more with display:block */
 		prerequisites: { "display": "block" },
 		initial_values: [ " auto" ],
 		/* XXX these have prerequisites */
 		other_values: [ "15px", "3em", "15%", "-moz-max-content", "-moz-min-content", "-moz-fit-content", "-moz-available",
+			"3e1px", "3e+1px", "3e0px", "3e+0px", "3e-0px", "3e-1px",
+			"3.2e1px", "3.2e+1px", "3.2e0px", "3.2e+0px", "3.2e-0px", "3.2e-1px",
+			"3e1%", "3e+1%", "3e0%", "3e+0%", "3e-0%", "3e-1%",
+			"3.2e1%", "3.2e+1%", "3.2e0%", "3.2e+0%", "3.2e-0%", "3.2e-1%",
 			/* valid -moz-calc() values */
 			"-moz-calc(-2px)",
 			"-moz-calc(2px)",
 			"-moz-calc(50%)",
 			"-moz-calc(50% + 2px)",
 			"-moz-calc( 50% + 2px)",
 			"-moz-calc(50% + 2px )",
 			"-moz-calc( 50% + 2px )",
@@ -3487,17 +3491,17 @@ var gCSSProperties = {
 	},
 	"z-index": {
 		domProp: "zIndex",
 		inherited: false,
 		type: CSS_TYPE_LONGHAND,
 		/* XXX requires position */
 		initial_values: [ "auto" ],
 		other_values: [ "0", "3", "-7000", "12000" ],
-		invalid_values: [ "3.0", "17.5" ]
+		invalid_values: [ "3.0", "17.5", "3e1" ]
 	}
 	,
 	"clip-path": {
 		domProp: "clipPath",
 		inherited: false,
 		type: CSS_TYPE_LONGHAND,
 		initial_values: [ "none" ],
 		other_values: [ "url(#mypath)", "url('404.svg#mypath')" ],