diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index db48285df..77721e01a 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -86,6 +86,9 @@ static void valueFlowBeforeCondition(TokenList *tokenlist, ErrorLogger *errorLog
         }
 
         const ValueFlow::Value val(tok, num);
+        ValueFlow::Value val2;
+        if (num==1 && var->typeStartToken()->isUnsigned() && Token::Match(tok,"<=|>="))
+            val2 = ValueFlow::Value(tok,0);
 
         for (Token *tok2 = tok->previous(); ; tok2 = tok2->previous()) {
             if (!tok2) {
@@ -117,6 +120,8 @@ static void valueFlowBeforeCondition(TokenList *tokenlist, ErrorLogger *errorLog
                 }
 
                 tok2->values.push_back(val);
+                if (val2.condition)
+                    tok2->values.push_back(val2);
                 if (var && tok2 == var->nameToken())
                     break;
             }
diff --git a/test/testother.cpp b/test/testother.cpp
index ac7e2c5ec..0ede33824 100644
--- a/test/testother.cpp
+++ b/test/testother.cpp
@@ -210,6 +210,7 @@ private:
         settings->inconclusive = inconclusive;
         settings->experimental = experimental;
         settings->standards.posix = posix;
+        settings->valueFlow = true;
 
         if (posix) {
             const char cfg[] = "<?xml version=\"1.0\"?>\n"
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
index 71904b601..bffbdedca 100644
--- a/test/testvalueflow.cpp
+++ b/test/testvalueflow.cpp
@@ -84,6 +84,13 @@ private:
                "}";
         ASSERT_EQUALS(true, testValueOfX(code, 2U, 123));
 
+        code = "void f(unsigned int x) {\n"
+               "    int a = x;\n"
+               "    if (x >= 1) {}\n"
+               "}";
+        ASSERT_EQUALS(true, testValueOfX(code, 2U, 1));
+        ASSERT_EQUALS(true, testValueOfX(code, 2U, 0));
+
         // bailout: ?:
         bailout("void f(int x) {\n"
                 "    y = ((x<0) ? x : ((x==2)?3:4));\n"