diff --git a/CHANGELOG.asciidoc b/CHANGELOG.asciidoc
index 3356f2a7b..7252e7cb1 100644
--- a/CHANGELOG.asciidoc
+++ b/CHANGELOG.asciidoc
@@ -38,6 +38,10 @@ endif::[]
 [[release-notes-3.9.0]]
 ==== 3.9.0 (2020-08-04)
 
+[float]
+===== Fixed
+- Scrub request body of illegal UTF-8 characters {pull}832[#832]
+
 [float]
 ===== Added
 
diff --git a/lib/elastic_apm/context_builder.rb b/lib/elastic_apm/context_builder.rb
index bd0c00b7b..54efe44e3 100644
--- a/lib/elastic_apm/context_builder.rb
+++ b/lib/elastic_apm/context_builder.rb
@@ -76,7 +76,7 @@ def get_body(req)
       else
         body = req.body.read
         req.body.rewind
-        body.byteslice(0, MAX_BODY_LENGTH).force_encoding('utf-8')
+        body.byteslice(0, MAX_BODY_LENGTH).force_encoding('utf-8').scrub
       end
     end
 
diff --git a/spec/elastic_apm/context_builder_spec.rb b/spec/elastic_apm/context_builder_spec.rb
index 97de34aa9..835dcabe9 100644
--- a/spec/elastic_apm/context_builder_spec.rb
+++ b/spec/elastic_apm/context_builder_spec.rb
@@ -112,6 +112,7 @@ module ElasticAPM
 
           expect(result.request.body).to eq '{"something":"everything"}'
           expect(result.request.body.encoding).to eq Encoding::UTF_8
+          expect(result.request.body.valid_encoding?).to be true
         end
       end
     end