diff --git a/CMakeLists.txt b/CMakeLists.txt
index 422a184..c6bde2f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -6,7 +6,7 @@ project(rpn)
 
 if((NOT CMAKE_BUILD_TYPE MATCHES Debug)
     AND (NOT CMAKE_BUILD_TYPE MATCHES Release))
-    set(CMAKE_BUILD_TYPE Release CACHE string "Choose the type of build, options are: None Debug Release" FORCE)
+    set(CMAKE_BUILD_TYPE Release CACHE STRING "Choose the type of build, options are: None Debug Release" FORCE)
 endif()
 
 message(STATUS "Build mode: ${CMAKE_BUILD_TYPE}")
diff --git a/src/lexer.cpp b/src/lexer.cpp
index afe433f..309a7eb 100644
--- a/src/lexer.cpp
+++ b/src/lexer.cpp
@@ -5,7 +5,7 @@ bool Lexer::lexer(string& entry, map<string, ReservedWord>& keywords, vector<Syn
     size_t jump;
     for (size_t i = 0; i < entry.size(); i++) {
         if (isspace(entry[i])) continue;
-        SynElement element;
+        SynElement element{.re = nullptr, .im = nullptr};
         switch (entry[i]) {
             case '"':
                 if (!parseString(entry, i, jump, errors, elements)) return false;
@@ -116,8 +116,7 @@ int Lexer::getBaseAt(string& entry, size_t& nextIdx, bool& positive) {
     if (entry[scan] == '+') {
         scan++;
         nextIdx = scan;
-    }
-    else if (entry[scan] == '-') {
+    } else if (entry[scan] == '-') {
         scan++;
         nextIdx = scan;
         positive = false;
@@ -169,8 +168,10 @@ bool Lexer::getNumberAt(string& entry, size_t idx, size_t& nextIdx, int& base, m
         if (mpfr_set_str((*r)->mpfr_ptr(), token.c_str(), base, mpreal::get_default_rnd()) == 0) {
             if (!positive) *(*r) = -*(*r);
             return true;
-        } else
-            return false;
+        } else {
+            delete *r;
+            return false;            
+        }
     }
     nextIdx = token.size() + idx + 1;
     return false;
@@ -206,16 +207,19 @@ bool Lexer::parseComplex(string& entry, size_t idx, size_t& nextIdx, vector<SynE
     }
 
     size_t i = nextIdx;
-    // while (i < entry.size() && entry[i] != ',') i++;
     if (i >= entry.size()) {
         elements.push_back({cmd_symbol, .value = entry.substr(idx, entry.size() - idx)});
         nextIdx = entry.size();
+        if (re != nullptr) delete re;
+        if (im != nullptr) delete im;
         return true;  // complex format error, return a symbol
     }
 
     if (!getNumberAt(entry, i, nextIdx, imBase, &im, ')')) {
         elements.push_back({cmd_symbol, .value = entry.substr(idx, entry.size() - idx)});
         nextIdx = entry.size();
+        if (re != nullptr) delete re;
+        if (im != nullptr) delete im;
         return true;  // complex format error, return a symbol
     }
     elements.push_back({cmd_complex, .re = re, .im = im, .reBase = reBase, .imBase = imBase});
diff --git a/src/program.cpp b/src/program.cpp
index aea896c..02ae9cf 100644
--- a/src/program.cpp
+++ b/src/program.cpp
@@ -612,7 +612,10 @@ ret_value program::parse(string& entry) {
                     break;
                 default:
                     show_error(ret_unknown_err, "error creating program from entry");
+                    break;
             }
+            if (element.re != nullptr) delete element.re;
+            if (element.im != nullptr) delete element.im;
         }
     } else
         for (SynError& err : errors) show_syntax_error(err.err.c_str());
diff --git a/test/mem_test.sh b/test/mem_test.sh
index 5c143f1..4fc101d 100755
--- a/test/mem_test.sh
+++ b/test/mem_test.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-rpn=../build/rpn
+rpn=../debug/rpn
 
 FG_RED="\033[0;31m"
 FG_GREEN="\033[0;32m"