diff --git a/.github/workflows/unit-tests.yml b/.github/workflows/unit-tests.yml
index fe0a2568c..7df511a69 100644
--- a/.github/workflows/unit-tests.yml
+++ b/.github/workflows/unit-tests.yml
@@ -18,12 +18,22 @@ jobs:
       fail-fast: false
       matrix:
         config:
-          - { os: "ubuntu-latest", R: "latest" }
-          - { os: "macOS-latest", R: "latest" }
+
+          # Check latest R versions
+          - { os: "ubuntu-latest",  R: "latest" }
+          - { os: "macOS-latest",   R: "latest" }
           - { os: "windows-latest", R: "latest" }
-          - { os: "ubuntu-latest", R: "devel" }
+          - { os: "ubuntu-latest",  R: "devel" }
           - { os: "windows-latest", R: "devel" }
 
+          # Check older versions of R
+          - { os: "ubuntu-latest",  R: 'oldrel-1'}
+          - { os: "ubuntu-latest",  R: 'oldrel-2'}
+          - { os: "ubuntu-latest",  R: 'oldrel-3'}
+          - { os: "ubuntu-latest",  R: 'oldrel-4'}
+
+          - { os: "windows-latest", R: "oldrel-4" }
+
     env:
       GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
       CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
diff --git a/paws.common/DESCRIPTION b/paws.common/DESCRIPTION
index 28316a776..45a13b7a9 100644
--- a/paws.common/DESCRIPTION
+++ b/paws.common/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: paws.common
 Type: Package
 Title: Paws Low-Level Amazon Web Services API
-Version: 0.8.7
+Version: 0.8.8
 Authors@R: c(
         person("David", "Kretch", email = "david.kretch@gmail.com", role = "aut"),
         person("Adam", "Banker", email = "adam.banker39@gmail.com", role = "aut"),
@@ -14,6 +14,7 @@ Description: Functions for making low-level API requests to Amazon Web Services
     higher-level interfaces to individual services, such as Simple Storage
     Service (S3).
 License: Apache License (>= 2.0)
+Depends: R (>= 4.1.0)
 URL: https://github.com/paws-r/paws, https://paws-r.r-universe.dev/paws.common, https://www.paws-r-sdk.com
 BugReports: https://github.com/paws-r/paws/issues
 Encoding: UTF-8
diff --git a/paws.common/NEWS.md b/paws.common/NEWS.md
index 3378a4c5e..1c012898a 100644
--- a/paws.common/NEWS.md
+++ b/paws.common/NEWS.md
@@ -1,3 +1,6 @@
+# paws.common 0.8.8
+* fix C++ compilation issues on older R versions by refactoring code to use C++11 standard and requiring R >= 4.1.0 (#957). Thanks to @detule for raising the issue.
+
 # paws.common 0.8.7
 * fix timezone handling in bearer token tests (#955). Thanks to @kyleam for raising issue.
 
diff --git a/paws.common/src/RcppExports.cpp b/paws.common/src/RcppExports.cpp
index 3c7a0ca97..7eee77425 100644
--- a/paws.common/src/RcppExports.cpp
+++ b/paws.common/src/RcppExports.cpp
@@ -68,7 +68,7 @@ BEGIN_RCPP
 END_RCPP
 }
 // json_build_any
-std::string json_build_any(SEXP values);
+CharacterVector json_build_any(SEXP values);
 RcppExport SEXP _paws_common_json_build_any(SEXP valuesSEXP) {
 BEGIN_RCPP
     Rcpp::RObject rcpp_result_gen;
diff --git a/paws.common/src/json_builder.cpp b/paws.common/src/json_builder.cpp
index 19c86372a..969e19ebd 100644
--- a/paws.common/src/json_builder.cpp
+++ b/paws.common/src/json_builder.cpp
@@ -67,7 +67,7 @@ inline std::string tag_get(SEXP object, const char *tag)
       case STRSXP:
         if (Rf_length(val) > 0)
         {
-          return std::string(CHAR(STRING_ELT(val, 0)));
+          return std::string(Rf_translateCharUTF8(STRING_ELT(val, 0)));
         }
         break;
       case LGLSXP:
@@ -135,8 +135,8 @@ std::string type(SEXP object)
 }
 
 // -------------------- Forward declaration --------------------
-// This function will be defined later and called recursively
-std::string json_build_any(SEXP values);
+// Internal function that builds JSON and returns std::string (used internally)
+std::string json_build_internal(SEXP values);
 
 // -------------------- Helper function to safely convert to string --------------------
 // This function converts an SEXP to a string representation, handling various R types.
@@ -151,17 +151,17 @@ std::string safe_as_string(SEXP x)
   switch (type)
   {
   case STRSXP:
-    // Directly return string for character SEXPs
-    return std::string(CHAR(STRING_ELT(x, 0)));
+    // Directly return string for character SEXPs, ensuring UTF-8 encoding
+    return std::string(Rf_translateCharUTF8(STRING_ELT(x, 0)));
   case INTSXP:
   case REALSXP:
   case LGLSXP:
   case RAWSXP:
     // Coerce to character and then return string for numeric, logical, raw
-    return std::string(CHAR(STRING_ELT(Rf_coerceVector(x, STRSXP), 0)));
+    return std::string(Rf_translateCharUTF8(STRING_ELT(Rf_coerceVector(x, STRSXP), 0)));
   default:
     // Coerce any other type to character as a fallback
-    return std::string(CHAR(STRING_ELT(Rf_coerceVector(x, STRSXP), 0)));
+    return std::string(Rf_translateCharUTF8(STRING_ELT(Rf_coerceVector(x, STRSXP), 0)));
   }
 }
 
@@ -255,7 +255,7 @@ std::string json_build_list(SEXP values)
   for (R_xlen_t i = 0; i < n; i++)
   {
     // Recursively build JSON for each element
-    std::string elem_json = json_build_any(VECTOR_ELT(values, i));
+    std::string elem_json = json_build_internal(VECTOR_ELT(values, i));
     // Only add non-empty elements, excluding "empty" JSON array/object strings
     if (!elem_json.empty() && elem_json != "[]" && elem_json != "{}")
     {
@@ -325,7 +325,7 @@ std::string json_build_structure(SEXP values)
     }
 
     // Recursively build JSON for the payload's value
-    return json_build_any(payload_val);
+    return json_build_internal(payload_val);
   }
 
   SEXP names = Rf_getAttrib(values, symbol_cache.names_sym);
@@ -360,11 +360,11 @@ std::string json_build_structure(SEXP values)
       val = uuid_val;                   // Use the newly created UUID SEXP
     }
 
-    std::string key = CHAR(STRING_ELT(names, i));         // Get the field name
+    std::string key = Rf_translateCharUTF8(STRING_ELT(names, i));         // Get the field name
     std::string loc_name = tag_get(val, "locationName");  // Check for locationName tag
     std::string name = loc_name.empty() ? key : loc_name; // Use locationName if present
 
-    std::string json_val = json_build_any(val); // Recursively build JSON for field value
+    std::string json_val = json_build_internal(val); // Recursively build JSON for field value
     // Only add non-empty fields, excluding "empty" JSON array/object strings
     if (!json_val.empty() && json_val != "[]" && json_val != "{}")
     {
@@ -420,14 +420,14 @@ inline std::string json_build_map(SEXP values)
   // Populate the vector with key-value pairs from the R object
   for (R_xlen_t i = 0; i < n; ++i)
   {
-    std::string key = CHAR(STRING_ELT(names_sexp, i));
+    std::string key = Rf_translateCharUTF8(STRING_ELT(names_sexp, i));
     SEXP val = VECTOR_ELT(values, i);
     named_elements.push_back({key, val});
   }
 
   // Sort the vector based on the string key in each pair
   std::sort(named_elements.begin(), named_elements.end(),
-            [](const auto &a, const auto &b)
+            [](const std::pair<std::string, SEXP> &a, const std::pair<std::string, SEXP> &b)
             {
               return a.first < b.first;
             });
@@ -442,7 +442,7 @@ inline std::string json_build_map(SEXP values)
     SEXP val = element.second;
 
     // Recursively build JSON for the value
-    std::string json_val = json_build_any(val);
+    std::string json_val = json_build_internal(val);
 
     // Only add non-empty pairs to the final JSON string
     if (!json_val.empty() && json_val != "[]" && json_val != "{}")
@@ -469,17 +469,8 @@ inline std::string json_build_map(SEXP values)
   return result;
 }
 
-/**
- * @brief Build Json Strings Using AWS Attributes for JSON Template
- *
- * @param object A list to be parsed into JSON string
- *
- * @return a JSON String
- */
-//' @useDynLib paws.common _paws_common_json_build_any
-//' @importFrom Rcpp evalCpp
-// [[Rcpp::export]]
-std::string json_build_any(SEXP values)
+// Internal implementation that returns std::string (used by recursive calls)
+std::string json_build_internal(SEXP values)
 {
   // Determine the effective type of the R object for JSON building
   std::string t = type(values);
@@ -494,3 +485,20 @@ std::string json_build_any(SEXP values)
   // Default to scalar if none of the above, or if `type` returns "scalar"
   return json_build_scalar(values);
 }
+
+/**
+ * @brief Build Json Strings Using AWS Attributes for JSON Template
+ *
+ * @param object A list to be parsed into JSON string
+ *
+ * @return a JSON String
+ */
+//' @useDynLib paws.common _paws_common_json_build_any
+//' @importFrom Rcpp evalCpp
+// [[Rcpp::export]]
+CharacterVector json_build_any(SEXP values)
+{
+  // Call internal implementation and UTF-8 encode result
+  std::string result = json_build_internal(values);
+  return CharacterVector::create(String(result, CE_UTF8));
+}
diff --git a/paws.common/src/json_escape.cpp b/paws.common/src/json_escape.cpp
index fbc1d9ba4..a90cf4cfd 100644
--- a/paws.common/src/json_escape.cpp
+++ b/paws.common/src/json_escape.cpp
@@ -143,6 +143,7 @@ CharacterVector json_convert_string(CharacterVector x)
   for (int i = 0; i < n; ++i)
   {
     String cur = x[i];
+    cur.set_encoding(CE_UTF8); // Ensure UTF-8 encoding
     out[i] = json_escape(cur);
   }
   return out;