diff --git a/tests/fixtures/language.sh b/tests/fixtures/language.sh
index ac827e0..a27b689 100644
--- a/tests/fixtures/language.sh
+++ b/tests/fixtures/language.sh
@@ -20,7 +20,7 @@ wget --user=admin --password= https://localhost
 mysqladmin create $DB_NAME --user="$DB_USER" --password="$DB_PASS"
 
 # Noncompliant
-API_TOKEN=${PLACEHOLDER-YXNkZmZmZmZm_HARDcoded}
+API_TOKEN=${API_TOKEN:-YXNkZmZmZmZm_HARDcoded}
 export DANGER_GITHUB_API_TOKEN=YXNkZmZmZmZm_HARDcoded
 export DANGER_GITHUB_API_TOKEN="YXNkZmZmZmZm_HARDcoded"
 # export COMMENTED_API_TOKEN="YXNkZmZmZmZm_HARDcoded"
diff --git a/whispers/core/utils.py b/whispers/core/utils.py
index d811b2f..2389ac2 100644
--- a/whispers/core/utils.py
+++ b/whispers/core/utils.py
@@ -20,7 +20,7 @@
 REGEX_PATH = re.compile(r"^((([A-Z]|file|root):)?(\.+)?[/\\]+).*$", flags=re.IGNORECASE)
 REGEX_IAC = re.compile(r"\![A-Za-z]+ .+", flags=re.IGNORECASE)
 REGEX_PRIVKEY_FILE = re.compile(r"(rsa|dsa|ed25519|ecdsa|pem|crt|cer|ca-bundle|p7b|p7c|p7s|ppk|pkcs12|pfx|p12)")
-REGEX_ENVVAR = re.compile(r"^\$\$?[A-Z0-9_]+$")
+REGEX_ENVVAR = re.compile(r"^\$\$?\{?[A-Z0-9_]+\}?$")
 
 
 def global_exception_handler(file: Union[str, Path], data: str):
diff --git a/whispers/plugins/shell.py b/whispers/plugins/shell.py
index fe10d31..4fefa4c 100644
--- a/whispers/plugins/shell.py
+++ b/whispers/plugins/shell.py
@@ -38,22 +38,26 @@ def read_commands(self, filepath: Path) -> Tuple[str, int]:
             yield " ".join(ret), lineno
             ret = []
 
-    def variables(self, cmd: List[str], lineno: int) -> Iterator[KeyValuePair]:
+    def variables(self, cmd: List[str], lineno: int = 0) -> Iterator[KeyValuePair]:
         """
         Checks if Shell variables contain a hardcoded or a default value.
         Examples:
             password="defaultPassword"
-            password=${ENV_VAR-defaultPassword}
+            password=${ENV_VAR:-defaultPassword}
         """
-        for item in cmd:
-            if "=" in item and len(item.split("=")) == 2:
-                key, value = item.split("=")  # Variable assignment
+        for value in cmd:
+            key = ""
 
-                if value.startswith("${") and value.endswith("}"):
-                    if "-" in value:
-                        value = value.split("-")[1].strip("}")  # Default value
+            if "=" in value and len(value.split("=")) == 2:
+                key, value = value.split("=")  # Variable assignment
 
-                yield KeyValuePair(key, value, line=lineno)
+            if ":-" in value and value.startswith("${") and value.endswith("}"):
+                key, value = value[2:-1].split(":-")  # Default value
+
+            if not (key or value):
+                continue
+
+            yield KeyValuePair(key, value, line=lineno)
 
     def curl(self, cmd: List[str], lineno: int) -> Iterator[KeyValuePair]:
         key = "password"
diff --git a/whispers/plugins/traverse.py b/whispers/plugins/traverse.py
index 9d5b324..b9890f5 100644
--- a/whispers/plugins/traverse.py
+++ b/whispers/plugins/traverse.py
@@ -2,6 +2,7 @@
 
 from whispers.models.pair import KeyValuePair
 from whispers.plugins.common import Common
+from whispers.plugins.shell import Shell
 
 
 class StructuredDocument:
@@ -34,11 +35,7 @@ def traverse(self, code, key=None) -> Optional[Iterator[KeyValuePair]]:
                 yield from self.traverse(item, key=key)
 
         elif isinstance(code, str):
-            if "=" in code:
-                item = code.split("=")
-                if len(item) == 2:
-                    yield KeyValuePair(item[0], item[1], list(self.keypath))
-
+            yield from Shell().variables([code])
             yield from Common(self.keypath).pairs(code)
 
     def cloudformation(self, code: dict) -> Iterator[KeyValuePair]: