diff --git a/cmake/phasar_macros.cmake b/cmake/phasar_macros.cmake
index 3a6d28dbb..2ce5cd45f 100644
--- a/cmake/phasar_macros.cmake
+++ b/cmake/phasar_macros.cmake
@@ -76,6 +76,13 @@ function(generate_ll_file)
   set(GEN_C_FLAGS -fno-discard-value-names -emit-llvm -S -w)
   set(GEN_CMD_COMMENT "[LL]")
 
+  if (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 15)
+    list(APPEND GEN_CXX_FLAGS -Xclang -no-opaque-pointers)
+  endif()
+  if (CMAKE_C_COMPILER_VERSION VERSION_GREATER_EQUAL 15)
+    list(APPEND GEN_C_FLAGS -Xclang -no-opaque-pointers)
+  endif()
+
   if(GEN_LL_MEM2REG)
     list(APPEND GEN_CXX_FLAGS -Xclang -disable-O0-optnone)
     list(APPEND GEN_C_FLAGS -Xclang -disable-O0-optnone)
@@ -121,7 +128,7 @@ function(generate_ll_file)
     add_custom_command(
       OUTPUT ${test_code_ll_file}
       COMMAND ${GEN_CMD} ${test_code_file_path} -o ${test_code_ll_file}
-      COMMAND ${CMAKE_CXX_COMPILER_LAUNCHER} opt -mem2reg -S ${test_code_ll_file} -o ${test_code_ll_file}
+      COMMAND ${CMAKE_CXX_COMPILER_LAUNCHER} opt -mem2reg -S -opaque-pointers=0 ${test_code_ll_file} -o ${test_code_ll_file}
       COMMENT ${GEN_CMD_COMMENT}
       DEPENDS ${GEN_LL_FILE}
       VERBATIM
diff --git a/include/phasar/PhasarLLVM/DataFlow/IfdsIde/Problems/IDEGeneralizedLCA/EdgeValue.h b/include/phasar/PhasarLLVM/DataFlow/IfdsIde/Problems/IDEGeneralizedLCA/EdgeValue.h
index c26a6191c..783698c91 100644
--- a/include/phasar/PhasarLLVM/DataFlow/IfdsIde/Problems/IDEGeneralizedLCA/EdgeValue.h
+++ b/include/phasar/PhasarLLVM/DataFlow/IfdsIde/Problems/IDEGeneralizedLCA/EdgeValue.h
@@ -10,6 +10,7 @@
 #ifndef PHASAR_PHASARLLVM_DATAFLOW_IFDSIDE_PROBLEMS_IDEGENERALIZEDLCA_EDGEVALUE_H
 #define PHASAR_PHASARLLVM_DATAFLOW_IFDSIDE_PROBLEMS_IDEGENERALIZEDLCA_EDGEVALUE_H
 
+#include "llvm/ADT/APFloat.h"
 #include "llvm/ADT/APSInt.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/IR/Constant.h"
diff --git a/lib/PhasarLLVM/DataFlow/IfdsIde/Problems/IDEGeneralizedLCA/IDEGeneralizedLCA.cpp b/lib/PhasarLLVM/DataFlow/IfdsIde/Problems/IDEGeneralizedLCA/IDEGeneralizedLCA.cpp
index b49ecb872..7ce08382f 100644
--- a/lib/PhasarLLVM/DataFlow/IfdsIde/Problems/IDEGeneralizedLCA/IDEGeneralizedLCA.cpp
+++ b/lib/PhasarLLVM/DataFlow/IfdsIde/Problems/IDEGeneralizedLCA/IDEGeneralizedLCA.cpp
@@ -29,12 +29,15 @@
 #include "phasar/Utils/Logger.h"
 
 #include "llvm/Demangle/Demangle.h"
+#include "llvm/IR/Constants.h"
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/InstrTypes.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/raw_ostream.h"
 
+#include <regex>
+
 namespace psr {
 
 using namespace glca;
@@ -669,11 +672,17 @@ bool IDEGeneralizedLCA::isEntryPoint(const std::string &Name) const {
 }
 
 bool IDEGeneralizedLCA::isStringConstructor(const llvm::Function *F) {
-  return (ICF->getSpecialMemberFunctionType(F) ==
-              SpecialMemberFunctionType::Constructor &&
-          llvm::demangle(F->getName().str())
-                  .find("::allocator<char> >::basic_string") !=
-              std::string::npos);
+  if (ICF->getSpecialMemberFunctionType(F) !=
+      SpecialMemberFunctionType::Constructor) {
+    return false;
+  }
+
+  static const std::regex StringCtorRex(
+      "::basic_string<std::allocator<char>[[:space:]]?>\\(",
+      std::regex::extended | std::regex::nosubs | std::regex::optimize);
+
+  auto DName = llvm::demangle(F->getName().str());
+  return std::regex_search(DName, StringCtorRex);
 }
 
 } // namespace psr
diff --git a/lib/PhasarLLVM/DataFlow/Mono/Problems/InterMonoFullConstantPropagation.cpp b/lib/PhasarLLVM/DataFlow/Mono/Problems/InterMonoFullConstantPropagation.cpp
index ca19e4c6f..b2c2365b9 100644
--- a/lib/PhasarLLVM/DataFlow/Mono/Problems/InterMonoFullConstantPropagation.cpp
+++ b/lib/PhasarLLVM/DataFlow/Mono/Problems/InterMonoFullConstantPropagation.cpp
@@ -16,6 +16,7 @@
 #include "phasar/PhasarLLVM/Utils/LLVMShorthands.h"
 #include "phasar/Utils/BitVectorSet.h"
 
+#include "llvm/IR/Constants.h"
 #include "llvm/IR/InstrTypes.h"
 #include "llvm/IR/Instruction.h"
 #include "llvm/IR/Instructions.h"
diff --git a/lib/PhasarLLVM/DataFlow/Mono/Problems/IntraMonoFullConstantPropagation.cpp b/lib/PhasarLLVM/DataFlow/Mono/Problems/IntraMonoFullConstantPropagation.cpp
index 2c415cd17..41aeb91a4 100644
--- a/lib/PhasarLLVM/DataFlow/Mono/Problems/IntraMonoFullConstantPropagation.cpp
+++ b/lib/PhasarLLVM/DataFlow/Mono/Problems/IntraMonoFullConstantPropagation.cpp
@@ -17,6 +17,7 @@
 #include "phasar/PhasarLLVM/Utils/LLVMShorthands.h"
 #include "phasar/Utils/BitVectorSet.h"
 
+#include "llvm/IR/Constants.h"
 #include "llvm/IR/Instruction.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/Value.h"
diff --git a/lib/PhasarLLVM/Pointer/LLVMBasedAliasAnalysis.cpp b/lib/PhasarLLVM/Pointer/LLVMBasedAliasAnalysis.cpp
index c41bb3347..bf5ad618c 100644
--- a/lib/PhasarLLVM/Pointer/LLVMBasedAliasAnalysis.cpp
+++ b/lib/PhasarLLVM/Pointer/LLVMBasedAliasAnalysis.cpp
@@ -24,6 +24,7 @@
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/Function.h"
+#include "llvm/IR/InstIterator.h"
 #include "llvm/IR/Instruction.h"
 #include "llvm/IR/PassManager.h"
 #include "llvm/IR/Value.h"
diff --git a/lib/PhasarLLVM/Pointer/external/llvm/CFLGraph.h b/lib/PhasarLLVM/Pointer/external/llvm/CFLGraph.h
index 1e50223cb..c3e53c114 100644
--- a/lib/PhasarLLVM/Pointer/external/llvm/CFLGraph.h
+++ b/lib/PhasarLLVM/Pointer/external/llvm/CFLGraph.h
@@ -436,7 +436,13 @@ template <typename CFLAA> class CFLGraphBuilder {
       // introduce any aliases.
       // TODO: address other common library functions such as realloc(),
       // strdup(), etc.
-      if (isMallocOrCallocLikeFn(&Call, &TLI) || isFreeCall(&Call, &TLI))
+      if (isMallocOrCallocLikeFn(&Call, &TLI) ||
+#if LLVM_VERSION_MAJOR >= 15
+          getFreedOperand(&Call, &TLI)
+#else
+          isFreeCall(&Call, &TLI)
+#endif
+      )
         return;
 
       // TODO: Add support for noalias args/all the other fun function
diff --git a/lib/PhasarLLVM/TaintConfig/LLVMTaintConfig.cpp b/lib/PhasarLLVM/TaintConfig/LLVMTaintConfig.cpp
index 99a1a277e..c7465cdd8 100644
--- a/lib/PhasarLLVM/TaintConfig/LLVMTaintConfig.cpp
+++ b/lib/PhasarLLVM/TaintConfig/LLVMTaintConfig.cpp
@@ -16,6 +16,7 @@
 #include "phasar/PhasarLLVM/Utils/LLVMShorthands.h"
 #include "phasar/Utils/Logger.h"
 
+#include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/InstIterator.h"
diff --git a/lib/PhasarLLVM/Utils/LLVMShorthands.cpp b/lib/PhasarLLVM/Utils/LLVMShorthands.cpp
index 82ba97330..99f809513 100644
--- a/lib/PhasarLLVM/Utils/LLVMShorthands.cpp
+++ b/lib/PhasarLLVM/Utils/LLVMShorthands.cpp
@@ -21,8 +21,10 @@
 
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/StringSwitch.h"
 #include "llvm/Bitcode/BitcodeReader.h"
 #include "llvm/Bitcode/BitcodeWriter.h"
+#include "llvm/IR/Constants.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/Instruction.h"