diff --git a/src/cmd_context/context_params.cpp b/src/cmd_context/context_params.cpp
index 85ac2274b..ff39907da 100644
--- a/src/cmd_context/context_params.cpp
+++ b/src/cmd_context/context_params.cpp
@@ -135,7 +135,7 @@ void context_params::set(char const * param, char const * value) {
 }
 
 void context_params::updt_params() {
-    updt_params(gparams::get());
+    updt_params(gparams::get_ref());
 }
 
 void context_params::updt_params(params_ref const & p) {
diff --git a/src/cmd_context/extra_cmds/dbg_cmds.cpp b/src/cmd_context/extra_cmds/dbg_cmds.cpp
index 465bcb956..fa1d56fe2 100644
--- a/src/cmd_context/extra_cmds/dbg_cmds.cpp
+++ b/src/cmd_context/extra_cmds/dbg_cmds.cpp
@@ -271,7 +271,7 @@ UNARY_CMD(elim_unused_vars_cmd, "dbg-elim-unused-vars", "<expr>", "eliminate unu
         return;
     }
     expr_ref r(ctx.m());
-    elim_unused_vars(ctx.m(), to_quantifier(arg), gparams::get(), r);
+    elim_unused_vars(ctx.m(), to_quantifier(arg), gparams::get_ref(), r);
     SASSERT(!is_quantifier(r) || !to_quantifier(r)->may_have_unused_vars());
     ctx.display(ctx.regular_stream(), r);
     ctx.regular_stream() << std::endl;
diff --git a/src/shell/lp_frontend.cpp b/src/shell/lp_frontend.cpp
index c79396cd1..ad9bcbd54 100644
--- a/src/shell/lp_frontend.cpp
+++ b/src/shell/lp_frontend.cpp
@@ -55,8 +55,8 @@ struct front_end_resource_limit : public lp::lp_resource_limit {
 void run_solver(lp_params & params, char const * mps_file_name) {
 
     reslimit rlim;
-    unsigned timeout = gparams::get().get_uint("timeout", 0);
-    unsigned rlimit  = gparams::get().get_uint("rlimit", 0);
+    unsigned timeout = gparams::get_ref().get_uint("timeout", 0);
+    unsigned rlimit  = gparams::get_ref().get_uint("rlimit", 0);
     front_end_resource_limit lp_limit(rlim);
 
     scoped_rlimit _rlimit(rlim, rlimit);
diff --git a/src/util/env_params.cpp b/src/util/env_params.cpp
index c2b5f7974..3ba6df735 100644
--- a/src/util/env_params.cpp
+++ b/src/util/env_params.cpp
@@ -23,7 +23,7 @@ Notes:
 #include "util/memory_manager.h"
 
 void env_params::updt_params() {
-    params_ref p = gparams::get();
+    params_ref const& p = gparams::get_ref();
     set_verbosity_level(p.get_uint("verbose", get_verbosity_level()));
     enable_warning_messages(p.get_bool("warning", true));
     memory::set_max_size(megabytes_to_bytes(p.get_uint("memory_max_size", 0)));
diff --git a/src/util/gparams.cpp b/src/util/gparams.cpp
index 12c335cdf..183525320 100644
--- a/src/util/gparams.cpp
+++ b/src/util/gparams.cpp
@@ -104,10 +104,8 @@ public:
 
     ~imp() {
         reset();
-        dictionary<param_descrs*>::iterator it  = m_module_param_descrs.begin();
-        dictionary<param_descrs*>::iterator end = m_module_param_descrs.end();
-        for (; it != end; ++it) {
-            dealloc(it->m_value);
+        for (auto & kv : m_module_param_descrs) {
+            dealloc(kv.m_value);
         }
     }
 
@@ -115,10 +113,8 @@ public:
         #pragma omp critical (gparams)
         {
             m_params.reset();
-            dictionary<params_ref*>::iterator it  = m_module_params.begin();
-            dictionary<params_ref*>::iterator end = m_module_params.end();
-            for (; it != end; ++it) {
-                dealloc(it->m_value);
+            for (auto & kv : m_module_params) {
+                dealloc(kv.m_value);
             }
             m_module_params.reset();
         }
@@ -437,14 +433,8 @@ public:
         return result;
     }
     
-    params_ref get() { 
-        params_ref result;
-        TRACE("gparams", tout << "get() m_params: " << m_params << "\n";);
-        #pragma omp critical (gparams)
-        {
-            result = m_params;
-        }
-        return result;
+    params_ref const& get_ref() { 
+        return m_params;
     }
 
     // -----------------------------------------------
@@ -464,16 +454,14 @@ public:
                 out << "Example:  pp.decimal=true\n";
                 out << "\n";
             }
-            dictionary<param_descrs*>::iterator it  = get_module_param_descrs().begin();
-            dictionary<param_descrs*>::iterator end = get_module_param_descrs().end();
-            for (; it != end; ++it) {
-                out << "[module] " << it->m_key;
+            for (auto & kv : get_module_param_descrs()) {
+                out << "[module] " << kv.m_key;
                 char const * descr = nullptr;
-                if (get_module_descrs().find(it->m_key, descr)) {
+                if (get_module_descrs().find(kv.m_key, descr)) {
                     out << ", description: " << descr;
                 }
                 out << "\n";
-                it->m_value->display(out, indent + 4, smt2_style, include_descr);
+                kv.m_value->display(out, indent + 4, smt2_style, include_descr);
             }
         }
     }
@@ -481,12 +469,10 @@ public:
     void display_modules(std::ostream & out) {
         #pragma omp critical (gparams)
         {
-            dictionary<param_descrs*>::iterator it  = get_module_param_descrs().begin();
-            dictionary<param_descrs*>::iterator end = get_module_param_descrs().end();
-            for (; it != end; ++it) {
-                out << "[module] " << it->m_key;
+            for (auto & kv : get_module_param_descrs()) {
+                out << "[module] " << kv.m_key;
                 char const * descr = nullptr;
-                if (get_module_descrs().find(it->m_key, descr)) {
+                if (get_module_descrs().find(kv.m_key, descr)) {
                     out << ", description: " << descr;
                 }
                 out << "\n";
@@ -618,10 +604,10 @@ params_ref gparams::get_module(symbol const & module_name) {
     return g_imp->get_module(module_name);
 }
 
-params_ref gparams::get() {
-    TRACE("gparams", tout << "gparams::get()\n";);
+params_ref const& gparams::get_ref() {
+    TRACE("gparams", tout << "gparams::get_ref()\n";);
     SASSERT(g_imp != 0);
-    return g_imp->get();
+    return g_imp->get_ref();
 }
 
 void gparams::display(std::ostream & out, unsigned indent, bool smt2_style, bool include_descr) {
diff --git a/src/util/gparams.h b/src/util/gparams.h
index 7ddaf0ccb..5334b28d0 100644
--- a/src/util/gparams.h
+++ b/src/util/gparams.h
@@ -106,7 +106,8 @@ public:
     /**
        \brief Return the global parameter set (i.e., parameters that are not associated with any particular module).
     */
-    static params_ref get();
+
+    static params_ref const& get_ref();
 
     /**
        \brief Dump information about available parameters in the given output stream.
diff --git a/src/util/params.cpp b/src/util/params.cpp
index 5e1e517c1..6bb6678cc 100644
--- a/src/util/params.cpp
+++ b/src/util/params.cpp
@@ -334,7 +334,10 @@ public:
     }
 
     void inc_ref() { m_ref_count++; }
-    void dec_ref() { SASSERT(m_ref_count > 0); m_ref_count--; if (m_ref_count == 0) dealloc(this); }
+    void dec_ref() { 
+        SASSERT(m_ref_count > 0); 
+        if (--m_ref_count == 0) dealloc(this); 
+    }
 
     bool empty() const { return m_entries.empty(); }
     bool contains(symbol const & k) const;
@@ -565,27 +568,25 @@ void params_ref::copy(params_ref const & src) {
 void params_ref::copy_core(params const * src) {
     if (src == nullptr)
         return;
-    svector<params::entry>::const_iterator it  = src->m_entries.begin();  
-    svector<params::entry>::const_iterator end = src->m_entries.end();    
-    for (; it != end; ++it) {
-        switch (it->second.m_kind) {
+    for (auto const& p : src->m_entries) {
+        switch (p.second.m_kind) {
         case CPK_BOOL:
-            m_params->set_bool(it->first, it->second.m_bool_value);
+            m_params->set_bool(p.first, p.second.m_bool_value);
             break;
         case CPK_UINT:
-            m_params->set_uint(it->first, it->second.m_uint_value);
+            m_params->set_uint(p.first, p.second.m_uint_value);
             break;
         case CPK_DOUBLE:
-            m_params->set_double(it->first, it->second.m_double_value);
+            m_params->set_double(p.first, p.second.m_double_value);
             break;
         case CPK_NUMERAL:
-            m_params->set_rat(it->first, *(it->second.m_rat_value));
+            m_params->set_rat(p.first, *(p.second.m_rat_value));
             break;
         case CPK_SYMBOL:
-            m_params->set_sym(it->first, symbol::mk_symbol_from_c_ptr(it->second.m_sym_value));
+            m_params->set_sym(p.first, symbol::mk_symbol_from_c_ptr(p.second.m_sym_value));
             break;
         case CPK_STRING:
-            m_params->set_str(it->first, it->second.m_str_value);
+            m_params->set_str(p.first, p.second.m_str_value);
             break;
         default:
             UNREACHABLE();