diff --git a/src/jsifier.js b/src/jsifier.js
index 1762d44ddd3e8..c58086868c58e 100644
--- a/src/jsifier.js
+++ b/src/jsifier.js
@@ -528,13 +528,6 @@ function JSify(data, functionsOnly) {
 
     var shellParts = read(shellFile).split('{{BODY}}');
     print(processMacros(preprocess(shellParts[1], shellFile)));
-    // Print out some useful metadata
-    if (RUNNING_JS_OPTS) {
-      var generatedFunctions = JSON.stringify(keys(Functions.implementedFunctions));
-      if (RUNNING_JS_OPTS) {
-        print('// EMSCRIPTEN_GENERATED_FUNCTIONS: ' + generatedFunctions + '\n');
-      }
-    }
 
     PassManager.serialize();
   }
diff --git a/src/parseTools.js b/src/parseTools.js
index 66263c9ce7fd8..376858739a8cd 100644
--- a/src/parseTools.js
+++ b/src/parseTools.js
@@ -628,7 +628,7 @@ function parseNumerical(value, type) {
       if (value[0] === '-' && ret === 0) { return '-.0'; } // fix negative 0, toString makes it 0
     }
     if (type === 'double' || type === 'float') {
-      if (!RUNNING_JS_OPTS) ret = asmEnsureFloat(ret, type);
+      ret = asmEnsureFloat(ret, type);
     }
     return ret.toString();
   } else {
@@ -747,8 +747,7 @@ function ensureDot(value) {
   value = value.toString();
   // if already dotted, or Infinity or NaN, nothing to do here
   // if smaller than 1 and running js opts, we always need to force a coercion (0.001 will turn into 1e-3, which has no .)
-  if ((value.indexOf('.') >= 0 || /[IN]/.test(value)) && (!RUNNING_JS_OPTS || Math.abs(value) >= 1)) return value;
-  if (RUNNING_JS_OPTS) return '(+' + value + ')'; // JS optimizer will run, we must do +x, and it will be corrected later
+  if ((value.indexOf('.') >= 0 || /[IN]/.test(value))) return value;
   var e = value.indexOf('e');
   if (e < 0) return value + '.0';
   return value.substr(0, e) + '.0' + value.substr(e);
@@ -772,7 +771,7 @@ function asmEnsureFloat(value, type) { // ensures that a float type has either 5
 function asmInitializer(type) {
   if (type in Compiletime.FLOAT_TYPES) {
     if (type === 'float') return 'Math_fround(0)';
-    return RUNNING_JS_OPTS ? '+0' : '.0';
+    return '.0';
   } else {
     return '0';
   }
diff --git a/src/settings.js b/src/settings.js
index 2c639861b0e4a..b7c5b23f09042 100644
--- a/src/settings.js
+++ b/src/settings.js
@@ -1045,9 +1045,6 @@ var EXPORT_NAME = 'Module';
 // to warnings instead of throwing an exception.
 var DYNAMIC_EXECUTION = 1;
 
-// whether js opts will be run, after the main compiler
-var RUNNING_JS_OPTS = 0;
-
 // whether we are in the generate struct_info bootstrap phase
 var BOOTSTRAPPING_STRUCT_INFO = 0;
 
@@ -1161,7 +1158,6 @@ var EMIT_EMSCRIPTEN_LICENSE = 0;
 // to automatically demote i64 to i32 and promote f32 to f64. This is necessary
 // in order to interface with JavaScript, both for asm.js and wasm.  For
 // non-web/non-JS embeddings, setting this to 0 may be desirable.
-// LEGALIZE_JS_FFI=0 is incompatible with RUNNING_JS_OPTS.
 var LEGALIZE_JS_FFI = 1;
 
 // Ports
@@ -1692,5 +1688,6 @@ var LEGACY_SETTINGS = [
   ['DEAD_FUNCTIONS', [[]], 'The wasm backend does not support dead function removal'],
   ['WASM_BACKEND', [-1], 'Only the wasm backend is now supported (note that setting it as -s has never been allowed anyhow)'],
   ['EXPORT_BINDINGS', [0, 1], 'No longer needed'],
+  ['RUNNING_JS_OPTS', [0], 'Fastcomp cared about running JS which could alter asm.js validation, but not upstream'],
   ['EXPORT_FUNCTION_TABLES', [0], 'No longer needed'],
 ];