diff --git a/modemm17/ClockRecovery.h b/modemm17/ClockRecovery.h
index 6d5d5ce05..3352a78fb 100644
--- a/modemm17/ClockRecovery.h
+++ b/modemm17/ClockRecovery.h
@@ -8,6 +8,8 @@
 #include <numeric>
 #include <cassert>
 
+#include "export.h"
+
 namespace modemm17
 {
 
@@ -37,7 +39,7 @@ namespace modemm17
  * @inv sample_index_ is in the interval [0, SAMPLES_PER_SYMBOL).
  * @inv clock_ is in the interval [0.9995, 1.0005]
  */
-class ClockRecovery
+class MODEMM17_API ClockRecovery
 {
     std::vector<float> estimates_;
     size_t sample_count_ = 0;
diff --git a/modemm17/LinkSetupFrame.h b/modemm17/LinkSetupFrame.h
index 1e45c8bdd..cfad92f64 100644
--- a/modemm17/LinkSetupFrame.h
+++ b/modemm17/LinkSetupFrame.h
@@ -8,10 +8,12 @@
 #include <stdexcept>
 #include <algorithm>
 
+#include "export.h"
+
 namespace modemm17
 {
 
-struct LinkSetupFrame
+struct MODEMM17_API LinkSetupFrame
 {
     using call_t = std::array<char,10>;             // NUL-terminated C-string.
     using encoded_call_t = std::array<uint8_t, 6>;
diff --git a/modemm17/M17Modulator.h b/modemm17/M17Modulator.h
index 45260a994..3e3959db1 100644
--- a/modemm17/M17Modulator.h
+++ b/modemm17/M17Modulator.h
@@ -21,6 +21,8 @@
 #include <iostream>
 #include <memory>
 
+#include "export.h"
+
 namespace modemm17
 {
 
@@ -29,7 +31,7 @@ namespace modemm17
  * It is used to produce the various symbol sequences but modulation is handled at
  * upper level.
  */
-struct M17Modulator
+struct MODEMM17_API M17Modulator
 {
 public:
     using symbols_t = std::array<int8_t, 192>;      // One frame of symbols.
diff --git a/modemm17/M17Randomizer.h b/modemm17/M17Randomizer.h
index a77b8374b..413d3d861 100644
--- a/modemm17/M17Randomizer.h
+++ b/modemm17/M17Randomizer.h
@@ -6,10 +6,11 @@
 #include <cstdint>
 #include <cstddef>
 
+#include "export.h"
 namespace modemm17
 {
 
-struct M17Randomizer
+struct MODEMM17_API M17Randomizer
 {
     std::array<int8_t, 368> dc_;