diff --git a/sql/src/main/java/io/crate/expression/scalar/regex/MatchesFunction.java b/sql/src/main/java/io/crate/expression/scalar/regex/MatchesFunction.java
index 257476387aa8..f7668ccf6a39 100644
--- a/sql/src/main/java/io/crate/expression/scalar/regex/MatchesFunction.java
+++ b/sql/src/main/java/io/crate/expression/scalar/regex/MatchesFunction.java
@@ -27,42 +27,50 @@
 import io.crate.expression.symbol.Literal;
 import io.crate.expression.symbol.Symbol;
 import io.crate.expression.symbol.SymbolType;
-import io.crate.metadata.BaseFunctionResolver;
 import io.crate.metadata.FunctionIdent;
-import io.crate.metadata.FunctionImplementation;
 import io.crate.metadata.FunctionInfo;
 import io.crate.metadata.Scalar;
 import io.crate.metadata.TransactionContext;
-import io.crate.metadata.functions.params.FuncParams;
-import io.crate.metadata.functions.params.Param;
-import io.crate.types.ArrayType;
-import io.crate.types.DataType;
+import io.crate.metadata.functions.Signature;
 import io.crate.types.DataTypes;
 
 import java.util.List;
 
+import static io.crate.types.TypeSignature.parseTypeSignature;
+
 public class MatchesFunction extends Scalar<List<String>, Object> {
 
     public static final String NAME = "regexp_matches";
-    private static final ArrayType<String> ARRAY_STRING_TYPE = new ArrayType<>(DataTypes.STRING);
 
     private FunctionInfo info;
     private RegexMatcher regexMatcher;
 
     public static void register(ScalarFunctionModule module) {
-        module.register(NAME,
-            new BaseFunctionResolver(
-                FuncParams.builder(Param.STRING, Param.STRING)
-                    .withVarArgs(Param.STRING).limitVarArgOccurrences(1)
-                    .build()) {
-
-                @Override
-                public FunctionImplementation getForTypes(List<DataType> dataTypes) throws IllegalArgumentException {
-                    DataType<?> innerType = dataTypes.get(0);
-                    return new MatchesFunction(
-                        new FunctionInfo(new FunctionIdent(NAME, dataTypes), new ArrayType<>(innerType)));
-                }
-            });
+        module.register(
+            Signature.scalar(
+                NAME,
+                parseTypeSignature("text"),
+                parseTypeSignature("text"),
+                parseTypeSignature("array(text)")
+            ),
+            args ->
+                new MatchesFunction(
+                    new FunctionInfo(new FunctionIdent(NAME, args), DataTypes.STRING_ARRAY)
+                )
+        );
+        module.register(
+            Signature.scalar(
+                NAME,
+                parseTypeSignature("text"),
+                parseTypeSignature("text"),
+                parseTypeSignature("text"),
+                parseTypeSignature("array(text)")
+            ),
+            args ->
+                new MatchesFunction(
+                    new FunctionInfo(new FunctionIdent(NAME, args), DataTypes.STRING_ARRAY)
+                )
+        );
     }
 
     private MatchesFunction(FunctionInfo info) {
@@ -102,7 +110,7 @@ public Symbol normalizeSymbol(Function symbol, TransactionContext txnCtx) {
         if (size == 3) {
             args[2] = (Input) symbol.arguments().get(2);
         }
-        return Literal.of(evaluate(txnCtx, args), ARRAY_STRING_TYPE);
+        return Literal.of(evaluate(txnCtx, args), DataTypes.STRING_ARRAY);
     }
 
     @Override
diff --git a/sql/src/main/java/io/crate/expression/scalar/regex/RegexpReplaceFunction.java b/sql/src/main/java/io/crate/expression/scalar/regex/RegexpReplaceFunction.java
index c2f8f62d11e7..6c9a1a0c4f0e 100644
--- a/sql/src/main/java/io/crate/expression/scalar/regex/RegexpReplaceFunction.java
+++ b/sql/src/main/java/io/crate/expression/scalar/regex/RegexpReplaceFunction.java
@@ -23,47 +23,54 @@
 
 import io.crate.data.Input;
 import io.crate.expression.scalar.ScalarFunctionModule;
-import io.crate.expression.symbol.FuncArg;
 import io.crate.expression.symbol.Function;
 import io.crate.expression.symbol.Literal;
 import io.crate.expression.symbol.Symbol;
 import io.crate.metadata.FunctionIdent;
-import io.crate.metadata.FunctionImplementation;
 import io.crate.metadata.FunctionInfo;
-import io.crate.metadata.FunctionResolver;
-import io.crate.metadata.TransactionContext;
 import io.crate.metadata.Scalar;
-import io.crate.metadata.functions.params.FuncParams;
-import io.crate.metadata.functions.params.Param;
-import io.crate.types.DataType;
+import io.crate.metadata.TransactionContext;
+import io.crate.metadata.functions.Signature;
 import io.crate.types.DataTypes;
 
 import javax.annotation.Nullable;
 import java.util.List;
 
-public class RegexpReplaceFunction extends Scalar<String, Object> implements FunctionResolver {
-
-    public static final String NAME = "regexp_replace";
+import static io.crate.types.TypeSignature.parseTypeSignature;
 
-    private final FuncParams funcParams = FuncParams.builder(
-        Param.STRING, Param.STRING, Param.STRING)
-        .withVarArgs(Param.STRING).limitVarArgOccurrences(1)
-        .build();
+public class RegexpReplaceFunction extends Scalar<String, Object> {
 
-    private static FunctionInfo createInfo(List<DataType> types) {
-        return new FunctionInfo(new FunctionIdent(NAME, types), DataTypes.STRING);
-    }
+    public static final String NAME = "regexp_replace";
 
     public static void register(ScalarFunctionModule module) {
-        module.register(NAME, new RegexpReplaceFunction());
+        module.register(
+            Signature.scalar(
+                NAME,
+                parseTypeSignature("text"),
+                parseTypeSignature("text"),
+                parseTypeSignature("text"),
+                parseTypeSignature("text")
+            ),
+            args ->
+                new RegexpReplaceFunction(new FunctionInfo(new FunctionIdent(NAME, args), DataTypes.STRING))
+        );
+        module.register(
+            Signature.scalar(
+                NAME,
+                parseTypeSignature("text"),
+                parseTypeSignature("text"),
+                parseTypeSignature("text"),
+                parseTypeSignature("text"),
+                parseTypeSignature("text")
+            ),
+            args ->
+                new RegexpReplaceFunction(new FunctionInfo(new FunctionIdent(NAME, args), DataTypes.STRING))
+        );
     }
 
     private FunctionInfo info;
     private RegexMatcher regexMatcher;
 
-    private RegexpReplaceFunction() {
-    }
-
     private RegexpReplaceFunction(FunctionInfo info) {
         this.info = info;
     }
@@ -143,17 +150,6 @@ public String evaluate(TransactionContext txnCtx, Input[] args) {
         return matcher.replace(val, replacement);
     }
 
-    @Override
-    public FunctionImplementation getForTypes(List<DataType> dataTypes) throws IllegalArgumentException {
-        return new RegexpReplaceFunction(createInfo(dataTypes));
-    }
-
-    @Nullable
-    @Override
-    public List<DataType> getSignature(List<? extends FuncArg> dataTypes) {
-        return funcParams.match(dataTypes);
-    }
-
     private static String eval(String value, String pattern, String replacement, @Nullable String flags) {
         RegexMatcher regexMatcher = new RegexMatcher(pattern, flags);
         return regexMatcher.replace(value, replacement);
diff --git a/sql/src/test/java/io/crate/expression/scalar/regex/RegexpReplaceFunctionTest.java b/sql/src/test/java/io/crate/expression/scalar/regex/RegexpReplaceFunctionTest.java
index 5fafa45a9dff..e7d6a798dea9 100644
--- a/sql/src/test/java/io/crate/expression/scalar/regex/RegexpReplaceFunctionTest.java
+++ b/sql/src/test/java/io/crate/expression/scalar/regex/RegexpReplaceFunctionTest.java
@@ -72,8 +72,8 @@ public void testNormalizeSymbolWithInvalidNumberOfArguments() throws Exception {
 
     @Test
     public void testNormalizeSymbolWithInvalidArgumentType() {
-        expectedException.expect(ConversionException.class);
-        expectedException.expectMessage("Cannot cast `'foobar'` of type `text` to type `bigint_array`");
+        expectedException.expect(UnsupportedOperationException.class);
+        expectedException.expectMessage("unknown function: regexp_replace(text, text, bigint_array)");
 
         assertNormalize("regexp_replace('foobar', '.*', [1,2])", isLiteral(""));
     }