diff --git a/src/linad99/derch.cpp b/src/linad99/derch.cpp
index dd15acad3..e1b26bd6a 100644
--- a/src/linad99/derch.cpp
+++ b/src/linad99/derch.cpp
@@ -42,7 +42,8 @@ void derch(const double& _f, const independent_variables & _x,
   double& f=(double&) _f;
   int& ireturn = (int&) _ireturn;
   independent_variables& x= (independent_variables&) _x;
-  static int i, n1 ,n2,ii;
+  [[maybe_unused]] static int i;
+  static int n1 ,n2,ii;
   static double fsave;
   static int order_flag;
   static double s, f1, f2, g2, xsave;
diff --git a/src/linad99/df_file.cpp b/src/linad99/df_file.cpp
index e68a578d6..165c6b676 100644
--- a/src/linad99/df_file.cpp
+++ b/src/linad99/df_file.cpp
@@ -146,7 +146,7 @@ DF_FILE::DF_FILE(const size_t nbytes, [[maybe_unused]] const unsigned int id)
   {
     buff = new char[buff_size];
   }
-  catch (const std::bad_alloc& e)
+  catch ([[maybe_unused]] const std::bad_alloc& e)
   {
     size_t gb = nbytes / 1073741824;
     cerr << "Error: Unable to construct DF_FILE memory buffer\n"
diff --git a/src/linad99/dmat34.cpp b/src/linad99/dmat34.cpp
index 00106a485..9e4aa79d7 100644
--- a/src/linad99/dmat34.cpp
+++ b/src/linad99/dmat34.cpp
@@ -122,7 +122,7 @@ dvector solve(const dmatrix& aa,const dvector& z,
   double* pvvj = &vv(lb);
   for (int j=lb;j<=ub;j++)
   {
-    dvector* pbbi = &bb(lb);
+    pbbi = &bb(lb);
     for (int i=lb;i<j;i++)
     {
       sum = *(pbbi->get_v() + j);
diff --git a/src/linad99/dvect9.cpp b/src/linad99/dvect9.cpp
index cbc31fa7b..b4012ffdd 100644
--- a/src/linad99/dvect9.cpp
+++ b/src/linad99/dvect9.cpp
@@ -227,7 +227,6 @@ dvector::dvector(const char* s)
     for (int i = 1; i <= count; ++i)
     {
       int index = 0;
-      char c;
       infile.get(c);
       while (!infile.eof())
       {
@@ -479,7 +478,6 @@ void dvector::allocate(const char* s)
     for (int i = 1; i <= count; ++i)
     {
       int index = 0;
-      char c;
       infile.get(c);
       while (!infile.eof())
       {
diff --git a/src/linad99/fvar_io2.cpp b/src/linad99/fvar_io2.cpp
index 90e9fc349..38ac92225 100644
--- a/src/linad99/fvar_io2.cpp
+++ b/src/linad99/fvar_io2.cpp
@@ -179,7 +179,6 @@ dvar_vector::dvar_vector(const char * s)
    for (i=1;i<=count;i++)
    {
      int index = 0;
-     char c;
      infile.get(c);
      while (!infile.eof())
      {
diff --git a/src/linad99/gst_read.cpp b/src/linad99/gst_read.cpp
index 6044fd98d..cdfbb87f0 100644
--- a/src/linad99/gst_read.cpp
+++ b/src/linad99/gst_read.cpp
@@ -124,7 +124,7 @@ int grad_stack::read_grad_stack_buffer(OFF_T& lpos)
 #if defined(DEBUG)
     assert(sizeof(grad_stack_entry) * length <= UINT_MAX);
 #endif
-    ssize_t nread = read(_GRADFILE_PTR, ptr_first, sizeof(grad_stack_entry)*length);
+    ssize_t nread = read(_GRADFILE_PTR, ptr_first, static_cast<unsigned int>(sizeof(grad_stack_entry)*length));
     ptr = ptr_first + length-1;
 
     if (nread == -1 )
diff --git a/src/linad99/jacob2.cpp b/src/linad99/jacob2.cpp
index e2a9d9e85..8b39c7ce9 100644
--- a/src/linad99/jacob2.cpp
+++ b/src/linad99/jacob2.cpp
@@ -169,11 +169,11 @@ void gradient_structure::jacobcalc(int nvar, const ofstream& _ofs)
 
     double_and_int* tmp = (double_and_int*)ARR_LIST1->ARRAY_MEMBLOCK_BASE;
 
-    unsigned long int max_last_offset = ARR_LIST1->get_max_last_offset();
+    unsigned long int local_max_last_offset = ARR_LIST1->get_max_last_offset();
 
     size_t size = sizeof(double_and_int );
 
-    for (unsigned int i = 0; i < (max_last_offset/size); i++)
+    for (unsigned int i = 0; i < (local_max_last_offset/size); i++)
     {
       tmp->x = 0;
 #if defined (__ZTC__)
diff --git a/src/linad99/jacob3.cpp b/src/linad99/jacob3.cpp
index dd9c15d2b..adc5fa618 100644
--- a/src/linad99/jacob3.cpp
+++ b/src/linad99/jacob3.cpp
@@ -157,11 +157,11 @@ void gradient_structure::jacobcalc(int nvar, const uostream& ofs)
 
     double_and_int* tmp = (double_and_int*)ARR_LIST1->ARRAY_MEMBLOCK_BASE;
 
-    unsigned long int max_last_offset = ARR_LIST1->get_max_last_offset();
+    unsigned long int local_max_last_offset = ARR_LIST1->get_max_last_offset();
 
     size_t size = sizeof(double_and_int);
 
-    for (unsigned int i = 0; i < (max_last_offset/size); i++)
+    for (unsigned int i = 0; i < (local_max_last_offset/size); i++)
     {
       tmp->x = 0;
 #if defined (__ZTC__)
diff --git a/src/linad99/jacobclc.cpp b/src/linad99/jacobclc.cpp
index 358ee6e10..dbe00bbe9 100644
--- a/src/linad99/jacobclc.cpp
+++ b/src/linad99/jacobclc.cpp
@@ -208,11 +208,11 @@ void gradient_structure::jacobcalc(int nvar, const dmatrix& _jac)
 
     double_and_int* tmp = (double_and_int*)ARR_LIST1->ARRAY_MEMBLOCK_BASE;
 
-    unsigned long int max_last_offset = ARR_LIST1->get_max_last_offset();
+    unsigned long int local_max_last_offset = ARR_LIST1->get_max_last_offset();
 
     size_t size = sizeof(double_and_int);
 
-    for (unsigned int i = 0; i < (max_last_offset/size); i++)
+    for (unsigned int i = 0; i < (local_max_last_offset/size); i++)
     {
       tmp->x = 0;
 #if defined (__ZTC__)
diff --git a/src/linad99/minim.cpp b/src/linad99/minim.cpp
index e2ad0be6e..b66ba6531 100644
--- a/src/linad99/minim.cpp
+++ b/src/linad99/minim.cpp
@@ -34,7 +34,7 @@ double fmm::minimize(const independent_variables & x,
   g.initialize();
 #endif
   {
-    gradient_structure gs;
+    gradient_structure local_gs;
     while (ireturn >= 0)
     {
       fmin(f,x,g);
diff --git a/src/linad99/sgradclc.cpp b/src/linad99/sgradclc.cpp
index 472fe9309..b4b99da48 100644
--- a/src/linad99/sgradclc.cpp
+++ b/src/linad99/sgradclc.cpp
@@ -266,7 +266,7 @@ void gradient_structure::save_arrays()
      LSEEK(GRAD_STACK1->_VARSSAV_PTR,0L,SEEK_SET);
 
 #if defined(DOS386)
-  #if (__cplusplus >= 201703L)
+  #ifndef DEBUG
      [[maybe_unused]]
   #endif
      ssize_t ret = write(GRAD_STACK1->_VARSSAV_PTR, (char*)src, bytes_needed);
@@ -326,7 +326,7 @@ void gradient_structure::restore_arrays()
     LSEEK(GRAD_STACK1->_VARSSAV_PTR,0L,SEEK_SET);
 
 #if defined(DOS386)
-  #if (__cplusplus >= 201703L)
+  #ifndef DEBUG
     [[maybe_unused]]
   #endif
     ssize_t ret = read(GRAD_STACK1->_VARSSAV_PTR, (char*)dest,bytes_needed);