diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index cf7acd8f6..dc54d0657 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -1148,11 +1148,29 @@ static bool valueFlowForward(Token * const               startToken,
             const bool condAlwaysTrue = (condTok && condTok->values.size() == 1U && condTok->values.front().isKnown() && condTok->values.front().intvalue != 0);
 
             // Should scope be skipped because variable value is checked?
-            std::list<ValueFlow::Value> truevalues;
+            std::list<ValueFlow::Value> truevalues, falsevalues;
             for (std::list<ValueFlow::Value>::const_iterator it = values.begin(); it != values.end(); ++it) {
                 if (condAlwaysTrue || !conditionIsFalse(condTok, getProgramMemory(tok2, varid, *it)))
                     truevalues.push_back(*it);
+                if (!condAlwaysTrue && !conditionIsTrue(condTok, getProgramMemory(tok2, varid, *it)))
+                    falsevalues.push_back(*it);
             }
+
+            if (!falsevalues.empty() && Token::simpleMatch(tok2->linkAt(1)->linkAt(1), "} else {")) {
+                // '{'
+                Token * const startToken1 = tok2->linkAt(1)->linkAt(1)->tokAt(2);
+
+                valueFlowForward(startToken1->next(),
+                                 startToken1->link(),
+                                 var,
+                                 varid,
+                                 falsevalues,
+                                 constValue,
+                                 tokenlist,
+                                 errorLogger,
+                                 settings);
+            }
+
             if (truevalues.size() != values.size() || condAlwaysTrue) {
                 // '{'
                 Token * const startToken1 = tok2->linkAt(1)->next();
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
index 751a83bb7..a07921b52 100644
--- a/test/testvalueflow.cpp
+++ b/test/testvalueflow.cpp
@@ -900,6 +900,13 @@ private:
                "}";
         ASSERT_EQUALS(false, testValueOfX(code, 4U, 4));
 
+        code = "void f(int y) {\n" // #3923
+               "  int x = 6;\n"
+               "  if (y) { x = 0; }\n"
+               "  else { a = x; }\n" // <- x is 6
+               "}";
+        ASSERT_EQUALS(true, testValueOfX(code, 4U, 6));
+
         code = "void f() {\n"
                "    int x = 32;\n"
                "    if (x>=32) return;\n"