diff --git a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/data/FunctionDefinitionDataType.java b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/data/FunctionDefinitionDataType.java
index c40471bcef..c3343b83dd 100644
--- a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/data/FunctionDefinitionDataType.java
+++ b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/data/FunctionDefinitionDataType.java
@@ -189,7 +189,8 @@ public class FunctionDefinitionDataType extends GenericDataType implements Funct
 
 		if (GenericCallingConvention
 				.getGenericCallingConvention(conventionName) == GenericCallingConvention.unknown &&
-			(dataMgr == null || !dataMgr.getKnownCallingConventionNames().contains(name))) {
+			(dataMgr == null ||
+				!dataMgr.getKnownCallingConventionNames().contains(conventionName))) {
 			throw new InvalidInputException("Unknown calling convention name: " + conventionName);
 		}
 
diff --git a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/pcode/HighFunctionDBUtil.java b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/pcode/HighFunctionDBUtil.java
index ad7d06df28..98ed7b6339 100644
--- a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/pcode/HighFunctionDBUtil.java
+++ b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/pcode/HighFunctionDBUtil.java
@@ -703,7 +703,8 @@ public class HighFunctionDBUtil {
 			throws InvalidInputException {
 
 		ParameterDefinition[] params = sig.getArguments();
-		FunctionDefinitionDataType fsig = new FunctionDefinitionDataType("tmpname"); // Empty datatype, will get renamed later
+		FunctionDefinitionDataType fsig =
+			new FunctionDefinitionDataType("tmpname", function.getProgram().getDataTypeManager()); // Empty datatype, will get renamed later
 		fsig.setCallingConvention(sig.getCallingConventionName());
 		fsig.setArguments(params);
 		fsig.setReturnType(sig.getReturnType());