diff --git a/src/string/String.cpp b/src/string/String.cpp
index 17d9b33..2ff2dac 100644
--- a/src/string/String.cpp
+++ b/src/string/String.cpp
@@ -26,6 +26,8 @@ bool Hyprutils::String::isNumber(const std::string& str, bool allowfloat) {
     if (str.empty())
         return false;
 
+    bool decimalParsed = false;
+
     for (size_t i = 0; i < str.length(); ++i) {
         const char& c = str.at(i);
 
@@ -44,9 +46,11 @@ bool Hyprutils::String::isNumber(const std::string& str, bool allowfloat) {
             if (i == 0)
                 return false;
 
-            if (str.at(0) == '-')
+            if (decimalParsed)
                 return false;
 
+            decimalParsed = true;
+
             continue;
         }
     }
diff --git a/tests/string.cpp b/tests/string.cpp
index 67060ed..51cb3ad 100644
--- a/tests/string.cpp
+++ b/tests/string.cpp
@@ -30,6 +30,9 @@ int main(int argc, char** argv, char** envp) {
     EXPECT(isNumber("vvss", true), false);
     EXPECT(isNumber("0.9999s", true), false);
     EXPECT(isNumber("s0.9999", true), false);
+    EXPECT(isNumber("-1.0", true), true);
+    EXPECT(isNumber("-1..0", true), false);
+    EXPECT(isNumber("-10.0000000001", true), true);
 
     CVarList list("hello    world!", 0, 's', true);
     EXPECT(list[0], "hello");